diff --git a/pkgs/applications/networking/browsers/firefox/common.nix b/pkgs/applications/networking/browsers/firefox/common.nix
index dc52606f24b7..be1a1fbadb97 100644
--- a/pkgs/applications/networking/browsers/firefox/common.nix
+++ b/pkgs/applications/networking/browsers/firefox/common.nix
@@ -254,6 +254,25 @@ buildStdenv.mkDerivation {
       hash = "sha256-2IpdSyye3VT4VB95WurnyRFtdN1lfVtYpgEiUVhfNjw=";
     })
   ]
+  ++ [
+    # LLVM 19 turned on WASM reference types by default, exposing a bug
+    # that broke the Mozilla WASI build. Supposedly, it has been fixed
+    # upstream in LLVM, but the build fails in the same way for us even
+    # with LLVM 19 versions that contain the upstream patch.
+    #
+    # Apply the temporary patch Mozilla used to work around this bug
+    # for now until someone can investigate what’s going on here.
+    #
+    # TODO: Please someone figure out what’s up with this.
+    #
+    # See: <https://bugzilla.mozilla.org/show_bug.cgi?id=1905251>
+    # See: <https://github.com/llvm/llvm-project/pull/97451>
+    (fetchpatch {
+      name = "wasi-sdk-disable-reference-types.patch";
+      url = "https://hg.mozilla.org/integration/autoland/raw-rev/23a9f6555c7c";
+      hash = "sha256-CRywalJlRMFVLITEYXxpSq3jLPbUlWKNRHuKLwXqQfU=";
+    })
+  ]
   ++ extraPatches;
 
   postPatch = ''
diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index 736494b5ee55..1d907aa31f48 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -343,10 +343,6 @@ stdenvNoCC.mkDerivation {
       done
     ''
 
-    + optionalString targetPlatform.isDarwin ''
-      echo "-arch ${targetPlatform.darwinArch}" >> $out/nix-support/libc-ldflags
-    ''
-
     ##
     ## GNU specific extra strip flags
     ##
diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index 6caf5103325a..d9174df31a2a 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -696,10 +696,6 @@ stdenvNoCC.mkDerivation {
       done
     ''
 
-    + optionalString targetPlatform.isDarwin ''
-        echo "-arch ${targetPlatform.darwinArch}" >> $out/nix-support/cc-cflags
-    ''
-
     + optionalString targetPlatform.isAndroid ''
       echo "-D__ANDROID_API__=${targetPlatform.androidSdkVersion}" >> $out/nix-support/cc-cflags
     ''
diff --git a/pkgs/by-name/gs/gss/package.nix b/pkgs/by-name/gs/gss/package.nix
index 1271c52a4a8c..18020cf425f9 100644
--- a/pkgs/by-name/gs/gss/package.nix
+++ b/pkgs/by-name/gs/gss/package.nix
@@ -1,6 +1,8 @@
 { lib
 , stdenv
 , fetchurl
+, autoreconfHook
+, gtk-doc
 , withShishi ? !stdenv.hostPlatform.isDarwin
 , shishi
 }:
@@ -20,6 +22,8 @@ stdenv.mkDerivation rec {
     rm tests/krb5context.c
   '';
 
+  nativeBuildInputs = [ autoreconfHook gtk-doc ];
+
   buildInputs = lib.optional withShishi shishi;
 
   # ./stdint.h:89:5: error: expected value in expression
diff --git a/pkgs/by-name/mj/mjpegtools/package.nix b/pkgs/by-name/mj/mjpegtools/package.nix
index 147c30fed4c5..ba500f04385c 100644
--- a/pkgs/by-name/mj/mjpegtools/package.nix
+++ b/pkgs/by-name/mj/mjpegtools/package.nix
@@ -16,9 +16,15 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-sYBTbX2ZYLBeACOhl7ANyxAJKaSaq3HRnVX0obIQ9Jo=";
   };
 
-  # Clang 16 defaults to C++17. `std::auto_ptr` has been removed from C++17, and the
-  # `register` type class specifier is no longer allowed.
-  patches = [ ./c++-17-fixes.patch ];
+  patches = [
+    # Clang 16 defaults to C++17. `std::auto_ptr` has been removed from C++17,
+    # and the `register` type class specifier is no longer allowed.
+    ./c++-17-fixes.patch
+
+    # Clang-19 errors out for dead code (in header) which accesses undefined
+    # class members
+    ./remove-subtract-and-union-debug.diff
+  ];
 
   hardeningDisable = [ "format" ];
 
diff --git a/pkgs/by-name/mj/mjpegtools/remove-subtract-and-union-debug.diff b/pkgs/by-name/mj/mjpegtools/remove-subtract-and-union-debug.diff
new file mode 100644
index 000000000000..1d1ff88afcae
--- /dev/null
+++ b/pkgs/by-name/mj/mjpegtools/remove-subtract-and-union-debug.diff
@@ -0,0 +1,347 @@
+diff --git a/y4mdenoise/Region2D.hh b/y4mdenoise/Region2D.hh
+index b44e93f..ebc2821 100644
+--- a/y4mdenoise/Region2D.hh
++++ b/y4mdenoise/Region2D.hh
+@@ -97,35 +97,11 @@ public:
+ 		// Add the given horizontal extent to the region.  Note that
+ 		// a_tnXEnd is technically one past the end of the extent.
+ 
+-	template <class REGION, class REGION_TEMP>
+-	void UnionDebug (Status_t &a_reStatus, INDEX a_tnY,
+-			INDEX a_tnXStart, INDEX a_tnXEnd, REGION_TEMP &a_rTemp);
+-		// Add the given horizontal extent to the region.  Note that
+-		// a_tnXEnd is technically one past the end of the extent.
+-		// Exhaustively (i.e. slowly) verifies the results, using a
+-		// much simpler algorithm.
+-		// Requires the use of a temporary region, usually of the
+-		// final subclass' type, in order to work.  (Since that can't
+-		// be known at this level, a template parameter is included for
+-		// it.)
+-
+ 	template <class REGION>
+ 	void Union (Status_t &a_reStatus, const REGION &a_rOther);
+ 		// Make the current region represent the union between itself
+ 		// and the other given region.
+ 
+-	template <class REGION, class REGION_O, class REGION_TEMP>
+-	void UnionDebug (Status_t &a_reStatus,
+-			REGION_O &a_rOther, REGION_TEMP &a_rTemp);
+-		// Make the current region represent the union between itself
+-		// and the other given region.
+-		// Exhaustively (i.e. slowly) verifies the results, using a
+-		// much simpler algorithm.
+-		// Requires the use of a temporary region, usually of the
+-		// final subclass' type, in order to work.  (Since that can't
+-		// be known at this level, a template parameter is included for
+-		// it.)
+-
+ 	//void Merge (Status_t &a_reStatus, INDEX a_tnY, INDEX a_tnXStart,
+ 	//		INDEX a_tnXEnd);
+ 		// Merge this extent into the current region.
+@@ -166,37 +142,12 @@ public:
+ 		// Subtract the given horizontal extent from the region.  Note
+ 		// that a_tnXEnd is technically one past the end of the extent.
+ 
+-	template <class REGION_TEMP>
+-	void SubtractDebug (Status_t &a_reStatus, INDEX a_tnY,
+-			INDEX a_tnXStart, INDEX a_tnXEnd, REGION_TEMP &a_rTemp);
+-		// Subtract the given horizontal extent from the region.  Note
+-		// that a_tnXEnd is technically one past the end of the extent.
+-		// Exhaustively (i.e. slowly) verifies the results, using a
+-		// much simpler algorithm.
+-		// Requires the use of a temporary region, usually of the
+-		// final subclass' type, in order to work.  (Since that can't
+-		// be known at this level, a template parameter is included for
+-		// it.)
+-
+ 	template <class REGION>
+ 	void Subtract (Status_t &a_reStatus, const REGION &a_rOther);
+ 		// Subtract the other region from the current region, i.e.
+ 		// remove from the current region any extents that exist in the
+ 		// other region.
+ 	
+-	template <class REGION, class REGION_O, class REGION_TEMP>
+-	void SubtractDebug (Status_t &a_reStatus, REGION_O &a_rOther,
+-			REGION_TEMP &a_rTemp);
+-		// Subtract the other region from the current region, i.e.
+-		// remove from the current region any extents that exist in the
+-		// other region.
+-		// Exhaustively (i.e. slowly) verifies the results, using a
+-		// much simpler algorithm.
+-		// Requires the use of a temporary region, usually of the
+-		// final subclass' type, in order to work.  (Since that can't
+-		// be known at this level, a template parameter is included for
+-		// it.)
+-
+ 	//typedef ... ConstIterator;
+ 	//ConstIterator Begin (void) const { return m_setExtents.Begin(); }
+ 	//ConstIterator End (void) const { return m_setExtents.End(); }
+@@ -404,85 +355,6 @@ Region2D<INDEX,SIZE>::~Region2D()
+ 
+ 
+ 
+-// Add the given horizontal extent to the region.
+-template <class INDEX, class SIZE>
+-template <class REGION, class REGION_TEMP>
+-void
+-Region2D<INDEX,SIZE>::UnionDebug (Status_t &a_reStatus, INDEX a_tnY,
+-	INDEX a_tnXStart, INDEX a_tnXEnd, REGION_TEMP &a_rTemp)
+-{
+-	typename REGION::ConstIterator itHere;
+-	typename REGION_TEMP::ConstIterator itHereO;
+-	INDEX tnX;
+-		// Used to loop through points.
+-
+-	// Make sure they didn't start us off with an error.
+-	assert (a_reStatus == g_kNoError);
+-
+-	// Calculate the union.
+-	a_rTemp.Assign (a_reStatus, *this);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	a_rTemp.Union (a_reStatus, a_tnY, a_tnXStart, a_tnXEnd);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	
+-	// Loop through every point in the result, make sure it's in
+-	// one of the two input regions.
+-	for (itHereO = a_rTemp.Begin(); itHereO != a_rTemp.End(); ++itHereO)
+-	{
+-		const Extent &rHere = *itHereO;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!((rHere.m_tnY == a_tnY
+-				&& (tnX >= a_tnXStart && tnX < a_tnXEnd))
+-			|| this->DoesContainPoint (rHere.m_tnY, tnX)))
+-				goto error;
+-		}
+-	}
+-
+-	// Loop through every point in the original region, make sure
+-	// it's in the result.
+-	for (itHere = this->Begin(); itHere != this->End(); ++itHere)
+-	{
+-		const Extent &rHere = *itHere;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!a_rTemp.DoesContainPoint (rHere.m_tnY, tnX))
+-				goto error;
+-		}
+-	}
+-
+-	// Loop through every point in the added extent, make sure it's in
+-	// the result.
+-	for (tnX = a_tnXStart; tnX < a_tnXEnd; ++tnX)
+-	{
+-		if (!a_rTemp.DoesContainPoint (a_tnY, tnX))
+-			goto error;
+-	}
+-
+-	// The operation succeeded.  Commit it.
+-	Assign (a_reStatus, a_rTemp);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-
+-	// All done.
+-	return;
+-
+-error:
+-	// Handle deviations.
+-	fprintf (stderr, "Region2D::Union() failed\n");
+-	fprintf (stderr, "Input region:\n");
+-	PrintRegion (*this);
+-	fprintf (stderr, "Input extent: [%d,%d-%d]\n",
+-		int (a_tnY), int (a_tnXStart), int (a_tnXEnd));
+-	fprintf (stderr, "Result:\n");
+-	PrintRegion (a_rTemp);
+-	assert (false);
+-}
+-
+-
+-
+ // Make the current region represent the union between itself
+ // and the other given region.
+ template <class INDEX, class SIZE>
+@@ -513,182 +385,6 @@ Region2D<INDEX,SIZE>::Union (Status_t &a_reStatus,
+ 
+ 
+ 
+-// Make the current region represent the union between itself
+-// and the other given region.
+-template <class INDEX, class SIZE>
+-template <class REGION, class REGION_O, class REGION_TEMP>
+-void
+-Region2D<INDEX,SIZE>::UnionDebug (Status_t &a_reStatus,
+-	REGION_O &a_rOther, REGION_TEMP &a_rTemp)
+-{
+-	typename REGION::ConstIterator itHere;
+-	typename REGION_O::ConstIterator itHereO;
+-	typename REGION_TEMP::ConstIterator itHereT;
+-	INDEX tnX;
+-		// Used to loop through points.
+-
+-	// Make sure they didn't start us off with an error.
+-	assert (a_reStatus == g_kNoError);
+-
+-	// Calculate the union.
+-	a_rTemp.Assign (a_reStatus, *this);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	a_rTemp.Union (a_reStatus, a_rOther);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	
+-	// Loop through every point in the result, make sure it's in
+-	// one of the two input regions.
+-	for (itHereT = a_rTemp.Begin(); itHereT != a_rTemp.End(); ++itHereT)
+-	{
+-		const Extent &rHere = *itHereT;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!a_rOther.DoesContainPoint (rHere.m_tnY, tnX)
+-			&& !this->DoesContainPoint (rHere.m_tnY, tnX))
+-				goto error;
+-		}
+-	}
+-
+-	// Loop through every point in the first input region, make sure
+-	// it's in the result.
+-	for (itHere = this->Begin(); itHere != this->End(); ++itHere)
+-	{
+-		const Extent &rHere = *itHere;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!a_rTemp.DoesContainPoint (rHere.m_tnY, tnX))
+-				goto error;
+-		}
+-	}
+-
+-	// Loop through every point in the second input region, make sure
+-	// it's in the result.
+-	for (itHereO = a_rOther.Begin();
+-		 itHereO != a_rOther.End();
+-		 ++itHereO)
+-	{
+-		const Extent &rHere = *itHereO;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!a_rTemp.DoesContainPoint (rHere.m_tnY, tnX))
+-				goto error;
+-		}
+-	}
+-
+-	// The operation succeeded.  Commit it.
+-	Assign (a_reStatus, a_rTemp);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-
+-	// All done.
+-	return;
+-
+-error:
+-	// Handle deviations.
+-	fprintf (stderr, "Region2D::Union() failed\n");
+-	fprintf (stderr, "First input region:\n");
+-	PrintRegion (*this);
+-	fprintf (stderr, "Second input region:\n");
+-	PrintRegion (a_rOther);
+-	fprintf (stderr, "Result:\n");
+-	PrintRegion (a_rTemp);
+-	assert (false);
+-}
+-
+-
+-
+-// Subtract the other region from the current region, i.e.
+-// remove from the current region any areas that exist in the
+-// other region.
+-template <class INDEX, class SIZE>
+-template <class REGION, class REGION_O, class REGION_TEMP>
+-void
+-Region2D<INDEX,SIZE>::SubtractDebug (Status_t &a_reStatus,
+-	REGION_O &a_rOther, REGION_TEMP &a_rTemp)
+-{
+-	typename REGION::ConstIterator itHere;
+-	typename REGION_O::ConstIterator itHereO;
+-	typename REGION_TEMP::ConstIterator itHereT;
+-	INDEX tnX;
+-		// Used to loop through points.
+-
+-	// Make sure they didn't start us off with an error.
+-	assert (a_reStatus == g_kNoError);
+-
+-	// Calculate the difference.
+-	a_rTemp.Assign (a_reStatus, *this);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	a_rTemp.Subtract (a_reStatus, a_rOther);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-	
+-	// Loop through every point in the result, make sure it's in
+-	// the first input region but not the second.
+-	for (itHereT = a_rTemp.Begin(); itHereT != a_rTemp.End(); ++itHereT)
+-	{
+-		const Extent &rHere = *itHereT;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!(this->DoesContainPoint (rHere.m_tnY, tnX)
+-			&& !a_rOther.DoesContainPoint (rHere.m_tnY, tnX)))
+-				goto error;
+-		}
+-	}
+-
+-	// Loop through every point in the first input region, and if it's
+-	// not in the second input region, make sure it's in the result.
+-	for (itHere = this->Begin(); itHere != this->End(); ++itHere)
+-	{
+-		const Extent &rHere = *itHere;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (!a_rOther.DoesContainPoint (rHere.m_tnY, tnX))
+-			{
+-				if (!a_rTemp.DoesContainPoint (rHere.m_tnY, tnX))
+-					goto error;
+-			}
+-		}
+-	}
+-
+-	// Loop through every point in the second input region, make sure
+-	// it's not in the result.
+-	for (itHereO = a_rOther.Begin();
+-		 itHereO != a_rOther.End();
+-		 ++itHereO)
+-	{
+-		const Extent &rHere = *itHere;
+-		for (tnX = rHere.m_tnXStart; tnX < rHere.m_tnXEnd; ++tnX)
+-		{
+-			if (a_rTemp.DoesContainPoint (rHere.m_tnY, tnX))
+-				goto error;
+-		}
+-	}
+-
+-	// The operation succeeded.  Commit it.
+-	Assign (a_reStatus, a_rTemp);
+-	if (a_reStatus != g_kNoError)
+-		return;
+-
+-	// All done.
+-	return;
+-
+-error:
+-	// Handle deviations.
+-	fprintf (stderr, "Region2D::Subtract() failed\n");
+-	fprintf (stderr, "First input region:\n");
+-	PrintRegion (*this);
+-	fprintf (stderr, "Second input region:\n");
+-	PrintRegion (a_rOther);
+-	fprintf (stderr, "Result:\n");
+-	PrintRegion (a_rTemp);
+-	assert (false);
+-}
+-
+-
+-
+ // Flood-fill the current region.
+ template <class INDEX, class SIZE>
+ template <class CONTROL>
diff --git a/pkgs/by-name/nl/nlohmann_json/make-tests-build-clang-19.diff b/pkgs/by-name/nl/nlohmann_json/make-tests-build-clang-19.diff
new file mode 100644
index 000000000000..ceb869251469
--- /dev/null
+++ b/pkgs/by-name/nl/nlohmann_json/make-tests-build-clang-19.diff
@@ -0,0 +1,98 @@
+diff --git a/tests/src/unit-bson.cpp b/tests/src/unit-bson.cpp
+index 13216f2..fdfc350 100644
+--- a/tests/src/unit-bson.cpp
++++ b/tests/src/unit-bson.cpp
+@@ -621,7 +621,7 @@ TEST_CASE("BSON input/output_adapters")
+     {
+         SECTION("std::ostringstream")
+         {
+-            std::basic_ostringstream<std::uint8_t> ss;
++            std::basic_ostringstream<char> ss;
+             json::to_bson(json_representation, ss);
+             json j3 = json::from_bson(ss.str());
+             CHECK(json_representation == j3);
+diff --git a/tests/src/unit-cbor.cpp b/tests/src/unit-cbor.cpp
+index be94d2f..2b396b7 100644
+--- a/tests/src/unit-cbor.cpp
++++ b/tests/src/unit-cbor.cpp
+@@ -1881,7 +1881,7 @@ TEST_CASE("single CBOR roundtrip")
+         {
+             SECTION("std::ostringstream")
+             {
+-                std::basic_ostringstream<std::uint8_t> ss;
++                std::basic_ostringstream<char> ss;
+                 json::to_cbor(j1, ss);
+                 json j3 = json::from_cbor(ss.str());
+                 CHECK(j1 == j3);
+diff --git a/tests/src/unit-deserialization.cpp b/tests/src/unit-deserialization.cpp
+index 3bc161f..e4918b0 100644
+--- a/tests/src/unit-deserialization.cpp
++++ b/tests/src/unit-deserialization.cpp
+@@ -1131,13 +1131,11 @@ TEST_CASE("deserialization")
+     }
+ }
+ 
++
+ TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T,
+-                   char, unsigned char, signed char,
++                   char,
+                    wchar_t,
+-                   char16_t, char32_t,
+-                   std::uint8_t, std::int8_t,
+-                   std::int16_t, std::uint16_t,
+-                   std::int32_t, std::uint32_t)
++                   char16_t, char32_t)
+ {
+     std::vector<T> const v = {'t', 'r', 'u', 'e'};
+     CHECK(json::parse(v) == json(true));
+@@ -1163,7 +1161,7 @@ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-8)", T,
+ }
+ 
+ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-16)", T,
+-                   char16_t, std::uint16_t)
++                   char16_t)
+ {
+     // a star emoji
+     std::vector<T> const v = {static_cast<T>('"'), static_cast<T>(0x2b50), static_cast<T>(0xfe0f), static_cast<T>('"')};
+@@ -1176,7 +1174,7 @@ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-16)", T,
+ }
+ 
+ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-32)", T,
+-                   char32_t, std::uint32_t)
++                   char32_t)
+ {
+     // a star emoji
+     std::vector<T> const v = {static_cast<T>('"'), static_cast<T>(0x2b50), static_cast<T>(0xfe0f), static_cast<T>('"')};
+diff --git a/tests/src/unit-msgpack.cpp b/tests/src/unit-msgpack.cpp
+index 61162af..cfbb1fa 100644
+--- a/tests/src/unit-msgpack.cpp
++++ b/tests/src/unit-msgpack.cpp
+@@ -1604,7 +1604,7 @@ TEST_CASE("single MessagePack roundtrip")
+         {
+             SECTION("std::ostringstream")
+             {
+-                std::basic_ostringstream<std::uint8_t> ss;
++                std::basic_ostringstream<char> ss;
+                 json::to_msgpack(j1, ss);
+                 json j3 = json::from_msgpack(ss.str());
+                 CHECK(j1 == j3);
+diff --git a/tests/src/unit-regression2.cpp b/tests/src/unit-regression2.cpp
+index fab9aae..98947c5 100644
+--- a/tests/src/unit-regression2.cpp
++++ b/tests/src/unit-regression2.cpp
+@@ -674,6 +674,7 @@ TEST_CASE("regression tests 2")
+         CHECK(j.dump() == "{}");
+     }
+ 
++#if 0
+ #ifdef JSON_HAS_CPP_20
+ #if __has_include(<span>)
+     SECTION("issue #2546 - parsing containers of std::byte")
+@@ -684,6 +685,7 @@ TEST_CASE("regression tests 2")
+         CHECK(j.dump() == "\"Hello, world!\"");
+     }
+ #endif
++#endif
+ #endif
+ 
+     SECTION("issue #2574 - Deserialization to std::array, std::pair, and std::tuple with non-default constructable types fails")
diff --git a/pkgs/by-name/nl/nlohmann_json/package.nix b/pkgs/by-name/nl/nlohmann_json/package.nix
index d690cc45b2f9..8acc3d2d27ec 100644
--- a/pkgs/by-name/nl/nlohmann_json/package.nix
+++ b/pkgs/by-name/nl/nlohmann_json/package.nix
@@ -21,6 +21,12 @@ in stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-7F0Jon+1oWL7uqet5i1IgHX0fUw/+z0QwEcA3zs5xHg=";
   };
 
+  patches = lib.optionals stdenv.cc.isClang [
+    # tests fail to compile on clang-19
+    # https://github.com/nlohmann/json/issues/4490
+    ./make-tests-build-clang-19.diff
+  ];
+
   nativeBuildInputs = [ cmake ];
 
   cmakeFlags = [
diff --git a/pkgs/by-name/op/openjpeg/exclude-tests b/pkgs/by-name/op/openjpeg/exclude-tests
new file mode 100644
index 000000000000..060c48e8fe85
--- /dev/null
+++ b/pkgs/by-name/op/openjpeg/exclude-tests
@@ -0,0 +1,52 @@
+NR-C1P0-p0_04.j2k-compare2base
+NR-C1P0-p0_05.j2k-compare2base
+NR-C1P0-p0_06.j2k-compare2base
+NR-C1P1-p1_02.j2k-compare2base
+NR-C1P1-p1_03.j2k-compare2base
+NR-C1P1-p1_04.j2k-compare2base
+NR-C1P1-p1_05.j2k-compare2base
+NR-JP2-file2.jp2-compare2base
+NR-RIC-subsampling_1.jp2-compare2base
+NR-RIC-subsampling_2.jp2-compare2base
+NR-RIC-zoo1.jp2-compare2base
+NR-RIC-zoo2.jp2-compare2base
+NR-DEC-_00042.j2k-2-decode-md5
+NR-DEC-buxI.j2k-9-decode-md5
+NR-DEC-CT_Phillips_JPEG2K_Decompr_Problem.j2k-13-decode-md5
+NR-DEC-Marrin.jp2-18-decode-md5
+NR-DEC-kodak_2layers_lrcp.j2c-31-decode-md5
+NR-DEC-kodak_2layers_lrcp.j2c-32-decode-md5
+NR-DEC-file409752.jp2-40-decode-md5
+NR-DEC-issue188_beach_64bitsbox.jp2-41-decode-md5
+NR-DEC-issue206_image-000.jp2-42-decode-md5
+NR-DEC-issue205.jp2-43-decode-md5
+NR-DEC-issue228.j2k-60-decode-md5
+NR-DEC-issue142.j2k-66-decode-md5
+NR-DEC-issue134.jp2-67-decode-md5
+NR-DEC-issue135.j2k-68-decode-md5
+NR-DEC-issue208.jp2-69-decode-md5
+NR-DEC-issue211.jp2-70-decode-md5
+NR-DEC-issue226.j2k-74-decode
+NR-DEC-issue226.j2k-74-decode-md5
+NR-DEC-p1_04.j2k-124-decode-md5
+NR-DEC-p1_04.j2k-125-decode-md5
+NR-DEC-p1_04.j2k-126-decode-md5
+NR-DEC-p1_04.j2k-127-decode-md5
+NR-DEC-p1_04.j2k-128-decode-md5
+NR-DEC-p1_04.j2k-129-decode-md5
+NR-DEC-p1_04.j2k-131-decode-md5
+NR-DEC-p1_04.j2k-138-decode-md5
+NR-DEC-p1_04.j2k-140-decode-md5
+NR-DEC-p0_04.j2k-166-decode-md5
+NR-DEC-p0_04.j2k-167-decode-md5
+NR-DEC-p0_04.j2k-168-decode-md5
+NR-DEC-p0_04.j2k-172-decode-md5
+NR-DEC-issue205.jp2-253-decode-md5
+NR-DEC-issue236-ESYCC-CDEF.jp2-254-decode-md5
+NR-DEC-issue559-eci-090-CIELab.jp2-255-decode-md5
+NR-DEC-issue559-eci-091-CIELab.jp2-256-decode-md5
+NR-DEC-db11217111510058.jp2-306-decode-md5
+NR-DEC-tnsot_zero.jp2-307-decode-md5
+NR-DEC-Bretagne1_ht_lossy.j2k-311-decode-md5
+Found-But-No-Test-issue1472-bigloop.j2k
+Found-But-No-Test-small_world_non_consecutive_tilepart_tlm.jp2
diff --git a/pkgs/by-name/op/openjpeg/package.nix b/pkgs/by-name/op/openjpeg/package.nix
index 0bfa1067a7f7..15296d33b85d 100644
--- a/pkgs/by-name/op/openjpeg/package.nix
+++ b/pkgs/by-name/op/openjpeg/package.nix
@@ -1,5 +1,5 @@
 { lib, stdenv, fetchFromGitHub, cmake, pkg-config
-, libpng, libtiff, zlib, lcms2, jpylyzer
+, libpng, libtiff, zlib, lcms2
 , jpipLibSupport ? false # JPIP library & executables
 , jpipServerSupport ? false, curl, fcgi # JPIP Server
 , jdk
@@ -18,9 +18,15 @@
 }:
 
 let
-  mkFlag = optSet: flag: "-D${flag}=${if optSet then "ON" else "OFF"}";
+  # may need to get updated with package
+  # https://github.com/uclouvain/openjpeg-data
+  test-data = fetchFromGitHub {
+    owner = "uclouvain";
+    repo = "openjpeg-data";
+    rev = "a428429db695fccfc6d698bd13b6937dffd9d005";
+    hash = "sha256-udUi7sPNQJ5uCIAM8SqMGee6vRj1QbF9pLjdpNTQE5k=";
+  };
 in
-
 stdenv.mkDerivation rec {
   pname = "openjpeg";
   version = "2.5.2";
@@ -35,16 +41,15 @@ stdenv.mkDerivation rec {
   outputs = [ "out" "dev" ];
 
   cmakeFlags = [
-    "-DCMAKE_INSTALL_NAME_DIR=\${CMAKE_INSTALL_PREFIX}/lib"
-    "-DBUILD_SHARED_LIBS=ON"
+    (lib.cmakeBool "BUILD_SHARED_LIBS" (!stdenv.hostPlatform.isStatic))
     "-DBUILD_CODEC=ON"
     "-DBUILD_THIRDPARTY=OFF"
-    (mkFlag jpipLibSupport "BUILD_JPIP")
-    (mkFlag jpipServerSupport "BUILD_JPIP_SERVER")
+    (lib.cmakeBool "BUILD_JPIP" jpipLibSupport)
+    (lib.cmakeBool "BUILD_JPIP_SERVER" jpipServerSupport)
     "-DBUILD_VIEWER=OFF"
     "-DBUILD_JAVA=OFF"
-    (mkFlag doCheck "BUILD_TESTING")
-  ];
+    (lib.cmakeBool "BUILD_TESTING" doCheck)
+  ] ++ lib.optional doCheck "-DOPJ_DATA_ROOT=${test-data}";
 
   nativeBuildInputs = [ cmake pkg-config ];
 
@@ -52,12 +57,15 @@ stdenv.mkDerivation rec {
     ++ lib.optionals jpipServerSupport [ curl fcgi ]
     ++ lib.optional (jpipLibSupport) jdk;
 
-  doCheck = (!stdenv.hostPlatform.isAarch64 && !stdenv.hostPlatform.isPower64); # tests fail on aarch64-linux and powerpc64
-  nativeCheckInputs = [ jpylyzer ];
+  # tests did fail on powerpc64
+  doCheck = !stdenv.hostPlatform.isPower64
+    && stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+
   checkPhase = ''
-    substituteInPlace ../tools/ctest_scripts/travis-ci.cmake \
-      --replace "JPYLYZER_EXECUTABLE=" "JPYLYZER_EXECUTABLE=\"$(command -v jpylyzer)\" # "
-    OPJ_SOURCE_DIR=.. ctest -S ../tools/ctest_scripts/travis-ci.cmake
+    runHook preCheck
+    ctest -j $NIX_BUILD_CORES \
+          -E '.*jpylyser' --exclude-from-file ${./exclude-tests}
+    runHook postCheck
   '';
 
   passthru = {
diff --git a/pkgs/by-name/ra/rapidjson/char_traits-clang-19-errors.diff b/pkgs/by-name/ra/rapidjson/char_traits-clang-19-errors.diff
new file mode 100644
index 000000000000..c057b3c1ec6a
--- /dev/null
+++ b/pkgs/by-name/ra/rapidjson/char_traits-clang-19-errors.diff
@@ -0,0 +1,22 @@
+diff --git a/test/unittest/writertest.cpp b/test/unittest/writertest.cpp
+index 4c24121..66c9087 100644
+--- a/test/unittest/writertest.cpp
++++ b/test/unittest/writertest.cpp
+@@ -386,6 +386,9 @@ TEST(Writer, InvalidEncoding) {
+         writer.EndArray();
+     }
+ 
++
++    // does not compile on clang-19
++#if 0
+     // Fail in encoding
+     {
+         StringBuffer buffer;
+@@ -401,6 +404,7 @@ TEST(Writer, InvalidEncoding) {
+         static const UTF32<>::Ch s[] = { 0x110000, 0 }; // Out of U+0000 to U+10FFFF
+         EXPECT_FALSE(writer.String(s));
+     }
++#endif
+ }
+ 
+ TEST(Writer, ValidateEncoding) {
diff --git a/pkgs/by-name/ra/rapidjson/package.nix b/pkgs/by-name/ra/rapidjson/package.nix
index 09707dc75b9a..887beaa63051 100644
--- a/pkgs/by-name/ra/rapidjson/package.nix
+++ b/pkgs/by-name/ra/rapidjson/package.nix
@@ -29,6 +29,10 @@ stdenv.mkDerivation (finalAttrs: {
     ./use-nixpkgs-gtest.patch
     # https://github.com/Tencent/rapidjson/issues/2214
     ./suppress-valgrind-failures.patch
+
+    # disable tests which don't build on clang-19
+    # https://github.com/Tencent/rapidjson/issues/2318
+    ./char_traits-clang-19-errors.diff
   ];
 
   postPatch = ''
diff --git a/pkgs/by-name/ra/rav1e/package.nix b/pkgs/by-name/ra/rav1e/package.nix
index e8834ac131e4..dccb2d01a6b9 100644
--- a/pkgs/by-name/ra/rav1e/package.nix
+++ b/pkgs/by-name/ra/rav1e/package.nix
@@ -6,13 +6,11 @@
   fetchCrate,
   pkg-config,
   cargo-c,
-  darwin,
-  libgit2,
-  libiconv,
   nasm,
+  libgit2,
+  zlib,
   nix-update-script,
   testers,
-  zlib,
   rav1e,
 }:
 
@@ -25,22 +23,22 @@ rustPlatform.buildRustPackage rec {
     hash = "sha256-Db7qb7HBAy6lniIiN07iEzURmbfNtuhmgJRv7OUagUM=";
   };
 
-  cargoHash = "sha256-VyQ6n2kIJ7OjK6Xlf0T0GNsBvgESRETzKZDZzAn8ZuY=";
+  # update built to be able to use the system libgit2
+  cargoPatches = [ ./update-built.diff ];
+  cargoHash = "sha256-Ud9Vw31y8nLo0aC3j7XY1+mN/pRvH9gJ0uIq73hKy3Y=";
 
-  depsBuildBuild = [ pkg-config ];
+  depsBuildBuild = [
+    pkg-config
+    libgit2
+    zlib
+  ];
 
   nativeBuildInputs = [
     cargo-c
-    libgit2
     nasm
   ];
 
-  buildInputs =
-    [ zlib ]
-    ++ lib.optionals stdenv.hostPlatform.isDarwin [
-      libiconv
-      darwin.apple_sdk.frameworks.Security
-    ];
+  env.LIBGIT2_NO_VENDOR = 1;
 
   # Darwin uses `llvm-strip`, which results in link errors when using `-x` to strip the asm library
   # and linking it with cctools ld64.
diff --git a/pkgs/by-name/ra/rav1e/update-built.diff b/pkgs/by-name/ra/rav1e/update-built.diff
new file mode 100644
index 000000000000..3b2a027545d9
--- /dev/null
+++ b/pkgs/by-name/ra/rav1e/update-built.diff
@@ -0,0 +1,40 @@
+diff --git a/Cargo.lock b/Cargo.lock
+index 6825377..8512eba 100644
+--- a/Cargo.lock
++++ b/Cargo.lock
+@@ -242,9 +242,9 @@ dependencies = [
+ 
+ [[package]]
+ name = "built"
+-version = "0.7.1"
++version = "0.7.5"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "38d17f4d6e4dc36d1a02fbedc2753a096848e7c1b0772f7654eab8e2c927dd53"
++checksum = "c360505aed52b7ec96a3636c3f039d99103c37d1d9b4f7a8c743d3ea9ffcd03b"
+ dependencies = [
+  "git2",
+ ]
+@@ -633,9 +633,9 @@ checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
+ 
+ [[package]]
+ name = "git2"
+-version = "0.18.1"
++version = "0.19.0"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "fbf97ba92db08df386e10c8ede66a2a0369bd277090afd8710e19e38de9ec0cd"
++checksum = "b903b73e45dc0c6c596f2d37eccece7c1c8bb6e4407b001096387c63d0d93724"
+ dependencies = [
+  "bitflags 2.4.1",
+  "libc",
+@@ -845,9 +845,9 @@ dependencies = [
+ 
+ [[package]]
+ name = "libgit2-sys"
+-version = "0.16.1+1.7.1"
++version = "0.17.0+1.8.1"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "f2a2bb3680b094add03bb3732ec520ece34da31a8cd2d633d1389d0f0fb60d0c"
++checksum = "10472326a8a6477c3c20a64547b0059e4b0d086869eee31e6d7da728a8eb7224"
+ dependencies = [
+  "cc",
+  "libc",
diff --git a/pkgs/by-name/sp/spdlog/package.nix b/pkgs/by-name/sp/spdlog/package.nix
index 6aa91db83549..0c9777b1ca88 100644
--- a/pkgs/by-name/sp/spdlog/package.nix
+++ b/pkgs/by-name/sp/spdlog/package.nix
@@ -41,6 +41,11 @@ stdenv.mkDerivation rec {
   postInstall = ''
     mkdir -p $out/share/doc/spdlog
     cp -rv ../example $out/share/doc/spdlog
+
+    substituteInPlace $dev/include/spdlog/tweakme.h \
+      --replace-fail \
+        '// #define SPDLOG_FMT_EXTERNAL' \
+        '#define SPDLOG_FMT_EXTERNAL'
   '';
 
   doCheck = true;
diff --git a/pkgs/by-name/xc/xcbuild/patches/Use-system-toolchain-for-usr-bin.patch b/pkgs/by-name/xc/xcbuild/patches/Use-system-toolchain-for-usr-bin.patch
index f1b5a38fbcf0..d617b4206c1b 100644
--- a/pkgs/by-name/xc/xcbuild/patches/Use-system-toolchain-for-usr-bin.patch
+++ b/pkgs/by-name/xc/xcbuild/patches/Use-system-toolchain-for-usr-bin.patch
@@ -12,7 +12,7 @@ diff -Naur a/Libraries/xcsdk/Tools/xcrun.cpp b/Libraries/xcsdk/Tools/xcrun.cpp
  using libutil::FSUtil;
  
 +namespace {
-+  const std::vector<const std::string> kSystemDeveloperDirs = {
++  const std::vector<std::string> kSystemDeveloperDirs = {
 +    "/private/var/select/developer_dir",
 +    "/private/var/db/xcode_select_link"
 +  };
diff --git a/pkgs/by-name/xs/xsimd/package.nix b/pkgs/by-name/xs/xsimd/package.nix
index 622f11f400bc..ad806a6a7d46 100644
--- a/pkgs/by-name/xs/xsimd/package.nix
+++ b/pkgs/by-name/xs/xsimd/package.nix
@@ -26,6 +26,9 @@ stdenv.mkDerivation (finalAttrs: {
   ] ++ lib.optionals stdenv.hostPlatform.isDarwin [
     # https://github.com/xtensor-stack/xsimd/issues/1030
     ./disable-test_error_gamma.patch
+
+    # https://github.com/xtensor-stack/xsimd/issues/1063
+    ./relax-asin-precision.diff
   ];
 
   # strictDeps raises the chance that xsimd will be able to be cross compiled
diff --git a/pkgs/by-name/xs/xsimd/relax-asin-precision.diff b/pkgs/by-name/xs/xsimd/relax-asin-precision.diff
new file mode 100644
index 000000000000..7623f6e81e4a
--- /dev/null
+++ b/pkgs/by-name/xs/xsimd/relax-asin-precision.diff
@@ -0,0 +1,14 @@
+diff --git a/test/test_xsimd_api.cpp b/test/test_xsimd_api.cpp
+index f416ae9..1f8253e 100644
+--- a/test/test_xsimd_api.cpp
++++ b/test/test_xsimd_api.cpp
+@@ -468,7 +468,8 @@ struct xsimd_api_float_types_functions
+     void test_asin()
+     {
+         value_type val(1);
+-        CHECK_EQ(extract(xsimd::asin(T(val))), std::asin(val));
++        CHECK(extract(xsimd::asin(T(val)))
++              == doctest::Approx(std::asin(val)).epsilon(1e-7));
+     }
+     void test_asinh()
+     {
diff --git a/pkgs/by-name/zx/zxing-cpp/package.nix b/pkgs/by-name/zx/zxing-cpp/package.nix
index affac873f2cd..e162d3c40673 100644
--- a/pkgs/by-name/zx/zxing-cpp/package.nix
+++ b/pkgs/by-name/zx/zxing-cpp/package.nix
@@ -18,6 +18,12 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-teFspdATn9M7Z1vSr/7PdJx/xAv+TVai8rIekxqpBZk=";
   };
 
+  # c++ 20 needed for char8_t or clang-19 build fails
+  postPatch = ''
+    substituteInPlace CMakeLists.txt \
+      --replace-fail "CMAKE_CXX_STANDARD 17" "CMAKE_CXX_STANDARD 20"
+  '';
+
   nativeBuildInputs = [
     cmake
     pkg-config
diff --git a/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-09-1.diff b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-09-1.diff
new file mode 100644
index 000000000000..ee27f402956e
--- /dev/null
+++ b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-09-1.diff
@@ -0,0 +1,16 @@
+this patch fixes build for clang-18+
+
+diff --git a/libgcc/config/aarch64/lse.S b/libgcc/config/aarch64/lse.S
+index d3235bc33..1a56eb61c 100644
+--- a/libgcc/config/aarch64/lse.S
++++ b/libgcc/config/aarch64/lse.S
+@@ -170,8 +170,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ 	.globl	\name
+ 	.hidden	\name
+ 	.type	\name, %function
+-	.cfi_startproc
+ \name:
++	.cfi_startproc
+ 	BTI_C
+ .endm
+ 
diff --git a/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-14-1.diff b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-14-1.diff
new file mode 100644
index 000000000000..ea6dfe9c9b47
--- /dev/null
+++ b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-14-1.diff
@@ -0,0 +1,16 @@
+this patch fixes build for clang-18+
+
+diff --git a/libgcc/config/aarch64/lse.S b/libgcc/config/aarch64/lse.S
+index ecef47086..b478dd4d9 100644
+--- a/libgcc/config/aarch64/lse.S
++++ b/libgcc/config/aarch64/lse.S
+@@ -174,8 +174,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ 	.globl	\name
+ 	HIDDEN(\name)
+ 	SYMBOL_TYPE(\name, %function)
+-	.cfi_startproc
+ \name:
++	.cfi_startproc
+ .endm
+ 
+ .macro	ENDFN name
diff --git a/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-2.diff b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-2.diff
new file mode 100644
index 000000000000..83aecff1a0df
--- /dev/null
+++ b/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-2.diff
@@ -0,0 +1,16 @@
+this patch fixes build for clang-18+
+
+diff --git a/libgcc/config/aarch64/lse.S b/libgcc/config/aarch64/lse.S
+index d3235bc33..1a56eb61c 100644
+--- a/libgcc/config/aarch64/lse.S
++++ b/libgcc/config/aarch64/lse.S
+@@ -197,8 +197,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ 	.text
+ 	.balign	16
+ 	.private_extern	_\name
+-	.cfi_startproc
+ _\name:
++	.cfi_startproc
+ 	BTI_C
+ .endm
+ 
diff --git a/pkgs/development/compilers/gcc/patches/default.nix b/pkgs/development/compilers/gcc/patches/default.nix
index 4e2518baff9e..0f2e8369eaad 100644
--- a/pkgs/development/compilers/gcc/patches/default.nix
+++ b/pkgs/development/compilers/gcc/patches/default.nix
@@ -40,6 +40,15 @@ let
   is9  = majorVersion == "9";
   is8  = majorVersion == "8";
   is7  = majorVersion == "7";
+
+  # We only apply these patches when building a native toolchain for
+  # aarch64-darwin, as it breaks building a foreign one:
+  # https://github.com/iains/gcc-12-branch/issues/18
+  canApplyIainsDarwinPatches = stdenv.hostPlatform.isDarwin
+    && stdenv.hostPlatform.isAarch64
+    && buildPlatform == hostPlatform
+    && hostPlatform == targetPlatform;
+
   inherit (lib) optionals optional;
 in
 
@@ -71,6 +80,8 @@ in
 ++ optional langFortran (if atLeast12 then ./gcc-12-gfortran-driving.patch else ./gfortran-driving.patch)
 ++ [ ./ppc-musl.patch ]
 ++ optional (atLeast9 && langD) ./libphobos.patch
+++ optional (atLeast9 && !atLeast14) ./cfi_startproc-reorder-label-09-1.diff
+++ optional (atLeast14 && !canApplyIainsDarwinPatches) ./cfi_startproc-reorder-label-14-1.diff
 
 
 
@@ -135,9 +146,7 @@ in
   "12" = [ ./gnat-darwin-dylib-install-name.patch ];
 }.${majorVersion} or [])
 
-# We only apply this patch when building a native toolchain for aarch64-darwin, as it breaks building
-# a foreign one: https://github.com/iains/gcc-12-branch/issues/18
-++ optionals (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64 && buildPlatform == hostPlatform && hostPlatform == targetPlatform) ({
+++ optionals canApplyIainsDarwinPatches ({
   "14" = [
     (fetchpatch {
       name = "gcc-14-darwin-aarch64-support.patch";
@@ -159,24 +168,24 @@ in
     name = "gcc-13-darwin-aarch64-support.patch";
     url = "https://raw.githubusercontent.com/Homebrew/formula-patches/bda0faddfbfb392e7b9c9101056b2c5ab2500508/gcc/gcc-13.3.0.diff";
     sha256 = "sha256-RBTCBXIveGwuQGJLzMW/UexpUZdDgdXprp/G2NHkmQo=";
-  }) ];
+  }) ./cfi_startproc-reorder-label-2.diff ];
   "12" = [ (fetchurl {
     name = "gcc-12-darwin-aarch64-support.patch";
     url = "https://raw.githubusercontent.com/Homebrew/formula-patches/1ed9eaea059f1677d27382c62f21462b476b37fe/gcc/gcc-12.4.0.diff";
     sha256 = "sha256-wOjpT79lps4TKG5/E761odhLGCphBIkCbOPiQg/D1Fw=";
-  }) ];
+  }) ./cfi_startproc-reorder-label-2.diff ];
   "11" = [ (fetchpatch {
     # There are no upstream release tags in https://github.com/iains/gcc-11-branch.
     # 5cc4c42a0d4de08715c2eef8715ad5b2e92a23b6 is the commit from https://github.com/gcc-mirror/gcc/releases/tag/releases%2Fgcc-11.5.0
     url = "https://github.com/iains/gcc-11-branch/compare/5cc4c42a0d4de08715c2eef8715ad5b2e92a23b6..gcc-11.5-darwin-r0.diff";
     hash = "sha256-7lH+GkgkrE6nOp9PMdIoqlQNWK31s6oW+lDt1LIkadE=";
-  }) ];
+  }) ./cfi_startproc-reorder-label-2.diff ];
   "10" = [ (fetchpatch {
     # There are no upstream release tags in https://github.com/iains/gcc-10-branch.
     # d04fe55 is the commit from https://github.com/gcc-mirror/gcc/releases/tag/releases%2Fgcc-10.5.0
     url = "https://github.com/iains/gcc-10-branch/compare/d04fe5541c53cb16d1ca5c80da044b4c7633dbc6...gcc-10-5Dr0-pre-0.diff";
     hash = "sha256-kVUHZKtYqkWIcqxHG7yAOR2B60w4KWLoxzaiFD/FWYk=";
-  }) ];
+  }) ./cfi_startproc-reorder-label-2.diff ];
 }.${majorVersion} or [])
 
 # Work around newer AvailabilityInternal.h when building older versions of GCC.
diff --git a/pkgs/development/compilers/llvm/common/clang/clang-unsupported-option.patch b/pkgs/development/compilers/llvm/common/clang/clang-unsupported-option.patch
new file mode 100644
index 000000000000..b265e7922c0d
--- /dev/null
+++ b/pkgs/development/compilers/llvm/common/clang/clang-unsupported-option.patch
@@ -0,0 +1,75 @@
+From 7ef5ed98cc6666f64db2f155ded2077ce038e1e4 Mon Sep 17 00:00:00 2001
+From: Reno Dakota <paparodeo@proton.me>
+Date: Sat, 16 Nov 2024 05:57:40 +0000
+Subject: [PATCH] [Clang][Driver] report unsupported option error regardless of
+ argument order
+
+This change updates clang to report unsupported option errors regardless
+of the command line argument order.
+
+When clang with a source file and without `-c` it will both compile and
+link. When an unsupported option is also part of the command line clang
+should generated an error. However, if the source file name comes before
+an object file, eg: `-lc`, the error is ignored.
+
+```
+$ clang --target=x86_64 -lc hello.c -mhtm
+clang: error: unsupported option '-mhtm' for target 'x86_64'
+$ echo $?
+1
+```
+
+but if `-lc` comes after `hello.c` the error is dropped
+
+```
+$ clang --target=x86_64 hello.c -mhtm -lc
+$ echo $?
+0
+```
+
+after this change clang will report the error regardless of the command
+line argument order.
+---
+ clang/lib/Driver/Driver.cpp            | 13 ++++++-------
+ clang/test/Driver/unsupported-option.c | 10 ++++++++++
+ 2 files changed, 16 insertions(+), 7 deletions(-)
+
+diff --git a/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
+index 93e85f7dffe35a..8e784a7b130ac3 100644
+--- a/lib/Driver/Driver.cpp
++++ b/lib/Driver/Driver.cpp
+@@ -4064,17 +4064,18 @@ void Driver::handleArguments(Compilation &C, DerivedArgList &Args,
+     YcArg = YuArg = nullptr;
+   }
+ 
+-  unsigned LastPLSize = 0;
++  bool LinkOnly = phases::Link == FinalPhase && Inputs.size() > 0;
+   for (auto &I : Inputs) {
+     types::ID InputType = I.first;
+     const Arg *InputArg = I.second;
+ 
+     auto PL = types::getCompilationPhases(InputType);
+-    LastPLSize = PL.size();
++
++    phases::ID InitialPhase = PL[0];
++    LinkOnly = LinkOnly && phases::Link == InitialPhase && PL.size() == 1;
+ 
+     // If the first step comes after the final phase we are doing as part of
+     // this compilation, warn the user about it.
+-    phases::ID InitialPhase = PL[0];
+     if (InitialPhase > FinalPhase) {
+       if (InputArg->isClaimed())
+         continue;
+@@ -4129,10 +4130,8 @@ void Driver::handleArguments(Compilation &C, DerivedArgList &Args,
+     }
+   }
+ 
+-  // If we are linking, claim any options which are obviously only used for
+-  // compilation.
+-  // FIXME: Understand why the last Phase List length is used here.
+-  if (FinalPhase == phases::Link && LastPLSize == 1) {
++  // claim any options which are obviously only used for compilation.
++  if (LinkOnly) {
+     Args.ClaimAllArgs(options::OPT_CompileOnly_Group);
+     Args.ClaimAllArgs(options::OPT_cl_compile_Group);
+   }
diff --git a/pkgs/development/compilers/llvm/common/default.nix b/pkgs/development/compilers/llvm/common/default.nix
index 33e4d3c998dd..b0d05c454a79 100644
--- a/pkgs/development/compilers/llvm/common/default.nix
+++ b/pkgs/development/compilers/llvm/common/default.nix
@@ -521,6 +521,12 @@ let
             (metadata.getVersionFile "clang/purity.patch")
             # https://reviews.llvm.org/D51899
             (metadata.getVersionFile "clang/gnu-install-dirs.patch")
+
+            # https://github.com/llvm/llvm-project/pull/116476
+            # prevent clang ignoring warnings / errors for unsuppored
+            # options when building & linking a source file with trailing
+            # libraries. eg: `clang -munsupported hello.c -lc`
+            ./clang/clang-unsupported-option.patch
           ]
           ++ lib.optional (lib.versions.major metadata.release_version == "13")
             # Revert of https://reviews.llvm.org/D100879
@@ -974,6 +980,15 @@ let
             lib.versionAtLeast metadata.release_version "14" && lib.versionOlder metadata.release_version "18"
           )
         ) (metadata.getVersionFile "compiler-rt/gnu-install-dirs.patch")
+        ++
+          lib.optional
+            (lib.versionAtLeast metadata.release_version "13" && lib.versionOlder metadata.release_version "18")
+            (fetchpatch {
+              name = "cfi_startproc-after-label.patch";
+              url = "https://github.com/llvm/llvm-project/commit/7939ce39dac0078fef7183d6198598b99c652c88.patch";
+              stripLen = 1;
+              hash = "sha256-tGqXsYvUllFrPa/r/dsKVlwx5IrcJGccuR1WAtUg7/o=";
+            })
         ++ [
           # ld-wrapper dislikes `-rpath-link //nix/store`, so we normalize away the
           # extra `/`.
diff --git a/pkgs/development/compilers/rust/1_82.nix b/pkgs/development/compilers/rust/1_82.nix
index 9d1281352ee1..45734f893dca 100644
--- a/pkgs/development/compilers/rust/1_82.nix
+++ b/pkgs/development/compilers/rust/1_82.nix
@@ -24,8 +24,8 @@
   pkgsTargetTarget,
   makeRustPlatform,
   wrapRustcWith,
-  llvmPackages_18,
-  llvm_18,
+  llvmPackages_19,
+  llvm_19,
   wrapCCWith,
   overrideCC,
   fetchpatch,
@@ -33,7 +33,7 @@
 let
   llvmSharedFor =
     pkgSet:
-    pkgSet.llvmPackages_18.libllvm.override (
+    pkgSet.llvmPackages_19.libllvm.override (
       {
         enableSharedLibraries = true;
       }
@@ -41,7 +41,7 @@ let
         # Force LLVM to compile using clang + LLVM libs when targeting pkgsLLVM
         stdenv = pkgSet.stdenv.override {
           allowedRequisites = null;
-          cc = pkgSet.pkgsBuildHost.llvmPackages_18.clangUseLLVM;
+          cc = pkgSet.pkgsBuildHost.llvmPackages_19.clangUseLLVM;
         };
       }
     );
@@ -68,14 +68,14 @@ import ./default.nix
             bootBintools ? if stdenv.targetPlatform.linker == "lld" then null else pkgs.bintools,
           }:
           let
-            llvmPackages = llvmPackages_18;
+            llvmPackages = llvmPackages_19;
 
             setStdenv =
               pkg:
               pkg.override {
                 stdenv = stdenv.override {
                   allowedRequisites = null;
-                  cc = pkgsBuildHost.llvmPackages_18.clangUseLLVM;
+                  cc = pkgsBuildHost.llvmPackages_19.clangUseLLVM;
                 };
               };
           in
@@ -88,7 +88,7 @@ import ./default.nix
             libcxx = llvmPackages.libcxx.override {
               stdenv = stdenv.override {
                 allowedRequisites = null;
-                cc = pkgsBuildHost.llvmPackages_18.clangNoLibcxx;
+                cc = pkgsBuildHost.llvmPackages_19.clangNoLibcxx;
                 hostPlatform = stdenv.hostPlatform // {
                   useLLVM = !stdenv.hostPlatform.isDarwin;
                 };
@@ -102,7 +102,7 @@ import ./default.nix
           }
         ) { }
       else
-        llvmPackages_18;
+        llvmPackages_19;
 
     # Note: the version MUST be the same version that we are building. Upstream
     # ensures that each released compiler can compile itself:
@@ -139,8 +139,8 @@ import ./default.nix
 
   (
     builtins.removeAttrs args [
-      "llvmPackages_18"
-      "llvm_18"
+      "llvmPackages_19"
+      "llvm_19"
       "wrapCCWith"
       "overrideCC"
       "fetchpatch"
diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index bd174babd549..c7f935d4288a 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -2578,9 +2578,36 @@ self: super: {
     testTarget = "tests";
   }) super.conduit-aeson;
 
-  # Upper bounds are too strict:
-  # https://github.com/velveteer/hermes/pull/22
-  hermes-json = doJailbreak super.hermes-json;
+  hermes-json = overrideCabal (drv: {
+    # Upper bounds are too strict:
+    # https://github.com/velveteer/hermes/pull/22
+    jailbreak = true;
+
+    # vendored simdjson breaks with clang-19. apply patches that work with
+    # a more recent simdjson so we can un-vendor it
+    patches = drv.patches or [] ++ [
+      (fetchpatch {
+        url = "https://github.com/velveteer/hermes/commit/6fd9904d93a5c001aadb27c114345a6958904d71.patch";
+        hash = "sha256-Pv09XP0/VjUiAFp237Adj06PIZU21mQRh7guTlKksvA=";
+        excludes = [
+          ".github/*"
+          "hermes-bench/*"
+        ];
+      })
+      (fetchpatch {
+        url = "https://github.com/velveteer/hermes/commit/ca8dddbf52f9d7788460a056fefeb241bcd09190.patch";
+        hash = "sha256-tDDGS0QZ3YWe7+SP09wnxx6lIWL986ce5Zhqr7F2sBk=";
+        excludes = [
+          "README.md"
+          ".github/*"
+          "hermes-bench/*"
+        ];
+      })
+    ];
+    postPatch = drv.postPatch or "" + ''
+      ln -fs ${pkgs.simdjson.src} simdjson
+    '';
+  }) super.hermes-json;
 
   # Disabling doctests.
   regex-tdfa = overrideCabal {
diff --git a/pkgs/development/libraries/aspell/default.nix b/pkgs/development/libraries/aspell/default.nix
index 8c152d32ef6c..c5ac805f6be5 100644
--- a/pkgs/development/libraries/aspell/default.nix
+++ b/pkgs/development/libraries/aspell/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, fetchzip, perl, ncurses
+{ lib, stdenv, fetchpatch, fetchurl, fetchzip, perl, ncurses
 
   # for tests
 , aspell, glibc, runCommand
@@ -27,7 +27,14 @@ stdenv.mkDerivation rec {
     hash = "sha256-1toSs01C1Ff6YE5DWtSEp0su/80SD/QKzWuz+yiH0hs=";
   };
 
-  patches = lib.optional searchNixProfiles ./data-dirs-from-nix-profiles.patch;
+  patches = [
+    # fix gcc-15 / clang-19 build. can remove on next update
+    (fetchpatch {
+      name = "fix-gcc-15-build.patch";
+      url = "https://github.com/GNUAspell/aspell/commit/ee6cbb12ff36a1e6618d7388a78dd4e0a2b44041.patch";
+      hash = "sha256-rW1FcfARdtT4wX+zGd2x/1K8zRp9JZhdR/zRd8RwPZA=";
+    })
+  ] ++ lib.optional searchNixProfiles ./data-dirs-from-nix-profiles.patch;
 
   postPatch = ''
     patch interfaces/cc/aspell.h < ${./clang.patch}
diff --git a/pkgs/development/libraries/catch2/3.nix b/pkgs/development/libraries/catch2/3.nix
index b005dc3f8116..fe83ce36bf0b 100644
--- a/pkgs/development/libraries/catch2/3.nix
+++ b/pkgs/development/libraries/catch2/3.nix
@@ -25,6 +25,7 @@ stdenv.mkDerivation rec {
   cmakeFlags = [
     "-DCATCH_DEVELOPMENT_BUILD=ON"
     "-DCATCH_BUILD_TESTING=${if doCheck then "ON" else "OFF"}"
+    "-DCATCH_ENABLE_WERROR=OFF"
   ] ++ lib.optionals (stdenv.hostPlatform.isDarwin && doCheck) [
     # test has a faulty path normalization technique that won't work in
     # our darwin build environment https://github.com/catchorg/Catch2/issues/1691
diff --git a/pkgs/development/libraries/fmt/default.nix b/pkgs/development/libraries/fmt/default.nix
index e2dcaadf5206..e4d6aaf99037 100644
--- a/pkgs/development/libraries/fmt/default.nix
+++ b/pkgs/development/libraries/fmt/default.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   cmake,
   enableShared ? !stdenv.hostPlatform.isStatic,
 
@@ -39,7 +40,7 @@ let
 
       nativeBuildInputs = [ cmake ];
 
-      cmakeFlags = [ "-DBUILD_SHARED_LIBS=${if enableShared then "ON" else "OFF"}" ];
+      cmakeFlags = [ (lib.cmakeBool "BUILD_SHARED_LIBS" enableShared) ];
 
       doCheck = true;
 
@@ -68,14 +69,16 @@ let
     };
 in
 {
-  fmt_8 = generic {
-    version = "8.1.1";
-    hash = "sha256-leb2800CwdZMJRWF5b1Y9ocK0jXpOX/nwo95icDf308=";
-  };
-
   fmt_9 = generic {
     version = "9.1.0";
     hash = "sha256-rP6ymyRc7LnKxUXwPpzhHOQvpJkpnRFOt2ctvUNlYI0=";
+    patches = [
+      # Fixes the build with Clang ≥ 18.
+      (fetchpatch {
+        url = "https://github.com/fmtlib/fmt/commit/c4283ec471bd3efdb114bc1ab30c7c7c5e5e0ee0.patch";
+        hash = "sha256-YyB5GY/ZqJQIhhGy0ICMPzfP/OUuyLnciiyv8Nscsec=";
+      })
+    ];
   };
 
   fmt_10 = generic {
@@ -86,5 +89,12 @@ in
   fmt_11 = generic {
     version = "11.0.2";
     hash = "sha256-IKNt4xUoVi750zBti5iJJcCk3zivTt7nU12RIf8pM+0=";
+    patches = [
+      (fetchpatch {
+        name = "get-rid-of-std-copy-fix-clang.patch";
+        url = "https://github.com/fmtlib/fmt/commit/6e462b89aa22fd5f737ed162d0150e145ccb1914.patch";
+        hash = "sha256-tRU1y1VCxtQ5J2yvFmwUx+YNcQs8izzLImD37KBiCFk=";
+      })
+    ];
   };
 }
diff --git a/pkgs/development/libraries/gettext/default.nix b/pkgs/development/libraries/gettext/default.nix
index 2a69b5702172..c5ca4a932fe6 100644
--- a/pkgs/development/libraries/gettext/default.nix
+++ b/pkgs/development/libraries/gettext/default.nix
@@ -8,11 +8,11 @@
 
 stdenv.mkDerivation rec {
   pname = "gettext";
-  version = "0.21.1";
+  version = "0.22.4";
 
   src = fetchurl {
     url = "mirror://gnu/gettext/${pname}-${version}.tar.gz";
-    sha256 = "sha256-6MNlDh2M7odcTzVWQjgsHfgwWL1aEe6FVcDPJ21kbUU=";
+    hash = "sha256-weC7KkQnqQJDkMZizVMtZkxLNrj/RE7V5UsRX9t6Guo=";
   };
   patches = [
     ./absolute-paths.diff
@@ -47,10 +47,25 @@ stdenv.mkDerivation rec {
   ];
 
   postPatch = ''
-   substituteAllInPlace gettext-runtime/src/gettext.sh.in
-   substituteInPlace gettext-tools/projects/KDE/trigger --replace "/bin/pwd" pwd
-   substituteInPlace gettext-tools/projects/GNOME/trigger --replace "/bin/pwd" pwd
-   substituteInPlace gettext-tools/src/project-id --replace "/bin/pwd" pwd
+    # Older versions of gettext come with a copy of `extern-inline.m4` that is not compatible with clang 18.
+    # When a project uses gettext + autoreconfPhase, autoreconfPhase will invoke `autopoint -f`, which will
+    # replace whatever (probably compatible) version of `extern-inline.m4` with one that probalby won’t work
+    # because `autopoint` will copy the autoconf macros from the project’s required version of gettext.
+    # Fixing this requires replacing all the older copies of the problematic file with a new one.
+    #
+    # This is ugly, but it avoids requiring workarounds in every package using gettext and autoreconfPhase.
+    declare -a oldFiles=($(tar tf gettext-tools/misc/archive.dir.tar | grep '^gettext-0\.[19].*/extern-inline.m4'))
+    oldFilesDir=$(mktemp -d)
+    for oldFile in "''${oldFiles[@]}"; do
+      mkdir -p "$oldFilesDir/$(dirname "$oldFile")"
+      cp gettext-tools/gnulib-m4/extern-inline.m4 "$oldFilesDir/$oldFile"
+    done
+    tar uf gettext-tools/misc/archive.dir.tar -C "$oldFilesDir" "''${oldFiles[@]}"
+
+    substituteAllInPlace gettext-runtime/src/gettext.sh.in
+    substituteInPlace gettext-tools/projects/KDE/trigger --replace "/bin/pwd" pwd
+    substituteInPlace gettext-tools/projects/GNOME/trigger --replace "/bin/pwd" pwd
+    substituteInPlace gettext-tools/src/project-id --replace "/bin/pwd" pwd
   '' + lib.optionalString stdenv.hostPlatform.isCygwin ''
     sed -i -e "s/\(cldr_plurals_LDADD = \)/\\1..\/gnulib-lib\/libxml_rpl.la /" gettext-tools/src/Makefile.in
     sed -i -e "s/\(libgettextsrc_la_LDFLAGS = \)/\\1..\/gnulib-lib\/libxml_rpl.la /" gettext-tools/src/Makefile.in
diff --git a/pkgs/development/libraries/kompute/default.nix b/pkgs/development/libraries/kompute/default.nix
index ced30a87dbfa..04b21d9ce026 100644
--- a/pkgs/development/libraries/kompute/default.nix
+++ b/pkgs/development/libraries/kompute/default.nix
@@ -6,41 +6,37 @@
 , vulkan-headers
 , vulkan-loader
 , fmt
+, spdlog
 , glslang
 , ninja
 }:
 
 stdenv.mkDerivation rec {
   pname = "kompute";
-  version = "0.8.1";
+  version = "0.9.0";
 
   src = fetchFromGitHub {
     owner = "KomputeProject";
     repo = "kompute";
     rev = "v${version}";
-    sha256 = "sha256-OkVGYh8QrD7JNqWFBLrDTYlk6IYHdvt4i7UtC4sQTzo=";
+    hash = "sha256-cf9Ef85R+VKao286+WHLgBWUqgwvuRocgeCzVJOGbdc=";
   };
 
-  patches = [
-    (fetchpatch {
-      url = "https://github.com/KomputeProject/kompute/commit/9a791b161dd58ca927fe090f65fa2b0e5e85e7ca.diff";
-      sha256 = "OtFTN8sgPlyiMmVzUnqzCkVMKj6DWxbCXtYwkRdEprY=";
-    })
-    (fetchpatch {
-      name = "enum-class-fix-for-fmt-8-x.patch";
-      url = "https://github.com/KomputeProject/kompute/commit/f731f2e55c7aaaa804111106c3e469f9a642d4eb.patch";
-      sha256 = "sha256-scTCYqkgKQnH27xzuY4FVbiwRuwBvChmLPPU7ZUrrL0=";
-    })
-  ];
-
   cmakeFlags = [
+    "-DKOMPUTE_OPT_USE_SPDLOG=ON"
+    # Doesn’t work without the vendored `spdlog`, and is redundant.
+    "-DKOMPUTE_OPT_LOG_LEVEL_DISABLED=ON"
+    "-DKOMPUTE_OPT_USE_BUILT_IN_SPDLOG=OFF"
+    "-DKOMPUTE_OPT_USE_BUILT_IN_FMT=OFF"
+    "-DKOMPUTE_OPT_USE_BUILT_IN_GOOGLE_TEST=OFF"
+    "-DKOMPUTE_OPT_USE_BUILT_IN_PYBIND11=OFF"
+    "-DKOMPUTE_OPT_USE_BUILT_IN_VULKAN_HEADER=OFF"
+    "-DKOMPUTE_OPT_DISABLE_VULKAN_VERSION_CHECK=ON"
     "-DKOMPUTE_OPT_INSTALL=1"
-    "-DRELEASE=1"
-    "-DKOMPUTE_ENABLE_SPDLOG=1"
   ];
 
   nativeBuildInputs = [ cmake ninja ];
-  buildInputs = [ fmt ];
+  buildInputs = [ fmt spdlog ];
   propagatedBuildInputs = [ glslang vulkan-headers vulkan-loader ];
 
   meta = with lib; {
diff --git a/pkgs/development/libraries/poppler/default.nix b/pkgs/development/libraries/poppler/default.nix
index 368c5a06a463..6ef6aca4b147 100644
--- a/pkgs/development/libraries/poppler/default.nix
+++ b/pkgs/development/libraries/poppler/default.nix
@@ -69,6 +69,14 @@ stdenv.mkDerivation (finalAttrs: rec {
       url = "https://gitlab.freedesktop.org/poppler/poppler/-/commit/0554731052d1a97745cb179ab0d45620589dd9c4.patch";
       hash = "sha256-I78wJ4l1DSh+x/e00ZL8uvrGdBH+ufp+EDm0A1XWyCU=";
     })
+
+    (fetchpatch {
+      # fixes build on clang-19
+      # https://gitlab.freedesktop.org/poppler/poppler/-/merge_requests/1526
+      name = "char16_t-not-short.patch";
+      url = "https://gitlab.freedesktop.org/poppler/poppler/-/commit/b4ac7d9af7cb5edfcfcbda035ed8b8c218ba8564.patch";
+      hash = "sha256-2aEq3VDITJabvB/+bcdULBXbqVbDdL0xJr2TWLiWqX8=";
+    })
   ];
 
   nativeBuildInputs = [
diff --git a/pkgs/development/libraries/qt-5/modules/qtbase.nix b/pkgs/development/libraries/qt-5/modules/qtbase.nix
index c61ce503f4f5..1ed4bfc8b2c2 100644
--- a/pkgs/development/libraries/qt-5/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtbase.nix
@@ -57,7 +57,7 @@ stdenv.mkDerivation (finalAttrs: ({
     libxml2 libxslt openssl sqlite zlib
 
     # Text rendering
-    harfbuzz icu
+    freetype harfbuzz icu
 
     # Image formats
     libjpeg libpng
@@ -67,7 +67,7 @@ stdenv.mkDerivation (finalAttrs: ({
       dbus glib udev
 
       # Text rendering
-      fontconfig freetype
+      fontconfig
 
       libdrm
 
@@ -323,6 +323,7 @@ stdenv.mkDerivation (finalAttrs: ({
     "-system-sqlite"
     ''-${if mysqlSupport then "plugin" else "no"}-sql-mysql''
     ''-${if postgresql != null then "plugin" else "no"}-sql-psql''
+    "-system-libpng"
 
     "-make libs"
     "-make tools"
@@ -332,8 +333,6 @@ stdenv.mkDerivation (finalAttrs: ({
     ++ (
       if stdenv.hostPlatform.isDarwin then [
       "-no-fontconfig"
-      "-qt-freetype"
-      "-qt-libpng"
       "-no-framework"
       "-no-rpath"
     ] else [
@@ -351,8 +350,6 @@ stdenv.mkDerivation (finalAttrs: ({
       ''-${lib.optionalString (cups == null) "no-"}cups''
       "-dbus-linked"
       "-glib"
-    ] ++ [
-      "-system-libpng"
     ] ++ lib.optional withGtk3 "-gtk"
       ++ lib.optional withLibinput "-libinput"
       ++ [
diff --git a/pkgs/development/libraries/qt-5/modules/qtlocation.nix b/pkgs/development/libraries/qt-5/modules/qtlocation.nix
index 35627af0c685..617a735baaa3 100644
--- a/pkgs/development/libraries/qt-5/modules/qtlocation.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtlocation.nix
@@ -4,6 +4,11 @@ qtModule {
   pname = "qtlocation";
   propagatedBuildInputs = [ qtbase qtmultimedia ];
   outputs = [ "bin" "out" "dev" ];
+  # Clang 18 treats a non-const, narrowing conversion in an initializer list as an error,
+  # which results in a failure building a 3rd party dependency of qtlocation. Just suppress it.
+  env = lib.optionalAttrs (stdenv.cc.isClang && (lib.versionAtLeast (lib.getVersion stdenv.cc) "18")) {
+    NIX_CFLAGS_COMPILE = "-Wno-c++11-narrowing-const-reference";
+  };
   qmakeFlags = lib.optionals stdenv.hostPlatform.isDarwin [
      # boost uses std::auto_ptr which has been disabled in clang with libcxx
      # This flag re-enables this feature
diff --git a/pkgs/development/libraries/qt-6/modules/qtquick3d.nix b/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
index 1c84856c0c12..fc40a408f4cc 100644
--- a/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
@@ -2,10 +2,19 @@
 , qtbase
 , qtdeclarative
 , openssl
+, fetchpatch
 }:
 
 qtModule {
   pname = "qtquick3d";
   propagatedBuildInputs = [ qtbase qtdeclarative ];
   buildInputs = [ openssl ];
+  patches = [
+    # should be able to remove on next update
+    (fetchpatch {
+      name = "fix-clang-19-build.patch";
+      url = "https://github.com/qt/qtquick3d/commit/636a5558470ba0e0a4db1ca23dc72d96dfabeccf.patch";
+      hash = "sha256-xBzOoVWDWvpxbSHKWeeWY1ZVldsjoUeJqFcfpvjEWAg=";
+    })
+  ];
 }
diff --git a/pkgs/development/libraries/wasilibc/default.nix b/pkgs/development/libraries/wasilibc/default.nix
index c0714a78556a..82df25395f82 100644
--- a/pkgs/development/libraries/wasilibc/default.nix
+++ b/pkgs/development/libraries/wasilibc/default.nix
@@ -8,7 +8,7 @@
 
 let
   pname = "wasilibc";
-  version = "21";
+  version = "22-unstable-2024-10-16";
 in
 stdenv.mkDerivation {
   inherit pname version;
@@ -16,8 +16,8 @@ stdenv.mkDerivation {
   src = buildPackages.fetchFromGitHub {
     owner = "WebAssembly";
     repo = "wasi-libc";
-    rev = "refs/tags/wasi-sdk-${version}";
-    hash = "sha256-1LsMpO29y79twVrUsuM/JvC7hK8O6Yey4Ard/S3Mvvc=";
+    rev = "98897e29fcfc81e2b12e487e4154ac99188330c4";
+    hash = "sha256-NFKhMJj/quvN3mR7lmxzA9w46KhX92iG0rQA9qDeS8I=";
     fetchSubmodules = true;
   };
 
diff --git a/pkgs/development/tools/documentation/doxygen/default.nix b/pkgs/development/tools/documentation/doxygen/default.nix
index 455f18ba0a3d..e3a0f9609c0e 100644
--- a/pkgs/development/tools/documentation/doxygen/default.nix
+++ b/pkgs/development/tools/documentation/doxygen/default.nix
@@ -15,23 +15,33 @@
 
 stdenv.mkDerivation rec {
   pname = "doxygen";
-  version = "1.10.0";
+  version = "1.12.0";
 
   src = fetchFromGitHub {
     owner = "doxygen";
     repo = "doxygen";
     rev = "Release_${lib.replaceStrings [ "." ] [ "_" ] version}";
-    sha256 = "sha256-FPI5ICdn9Tne/g9SP6jAQS813AAyoDNooDR/Hyvq6R4=";
+    hash = "sha256-4zSaM49TjOaZvrUChM4dNJLondCsQPSArOXZnTHS4yI=";
   };
 
   patches = [
+    # fix clang-19 build. can drop on next update
+    # https://github.com/doxygen/doxygen/pull/11064
     (fetchpatch {
-      name = "sys-spdlog-fix.patch";
-      url = "https://github.com/doxygen/doxygen/commit/0df6da616f01057d28b11c8bee28443c102dd424.patch";
-      hash = "sha256-7efkCQFYGslwqhIuPsLYTEiA1rq+mO0DuyQBMt0O+m0=";
+      name = "fix-clang-19-build.patch";
+      url = "https://github.com/doxygen/doxygen/commit/cff64a87dea7596fd506a85521d4df4616dc845f.patch";
+      hash = "sha256-TtkVfV9Ep8/+VGbTjP4NOP8K3p1+A78M+voAIQ+lzOk=";
     })
   ];
 
+  # https://github.com/doxygen/doxygen/issues/10928#issuecomment-2179320509
+  postPatch = ''
+    substituteInPlace CMakeLists.txt \
+      --replace-fail 'JAVACC_CHAR_TYPE=\"unsigned char\"' \
+                     'JAVACC_CHAR_TYPE=\"char8_t\"' \
+      --replace-fail "CMAKE_CXX_STANDARD 17" "CMAKE_CXX_STANDARD 20"
+  '';
+
   nativeBuildInputs = [
     cmake
     python3
@@ -49,9 +59,6 @@ stdenv.mkDerivation rec {
     "-Duse_sys_sqlite3=ON"
   ] ++ lib.optional (qt5 != null) "-Dbuild_wizard=YES";
 
-  env.NIX_CFLAGS_COMPILE =
-    lib.optionalString stdenv.hostPlatform.isDarwin "-mmacosx-version-min=10.9";
-
   # put examples in an output so people/tools can test against them
   outputs = [ "out" "examples" ];
   postInstall = ''
diff --git a/pkgs/development/web/nodejs/v18.nix b/pkgs/development/web/nodejs/v18.nix
index 6099d100675a..e8783fc314cd 100644
--- a/pkgs/development/web/nodejs/v18.nix
+++ b/pkgs/development/web/nodejs/v18.nix
@@ -1,19 +1,8 @@
-{ callPackage, lib, overrideCC, pkgs, buildPackages, openssl, python311, fetchpatch2, enableNpm ? true }:
+{ callPackage, lib, openssl, python311, fetchpatch2, enableNpm ? true }:
 
 let
-  # Clang 16+ cannot build Node v18 due to -Wenum-constexpr-conversion errors.
-  # Use an older version of clang with the current libc++ for compatibility (e.g., with icu).
-  ensureCompatibleCC = packages:
-    if packages.stdenv.cc.isClang && lib.versionAtLeast (lib.getVersion packages.stdenv.cc.cc) "16"
-      then overrideCC packages.llvmPackages_15.stdenv (packages.llvmPackages_15.stdenv.cc.override {
-        inherit (packages.llvmPackages) libcxx;
-      })
-      else packages.stdenv;
-
   buildNodejs = callPackage ./nodejs.nix {
     inherit openssl;
-    stdenv = ensureCompatibleCC pkgs;
-    buildPackages = buildPackages // { stdenv = ensureCompatibleCC buildPackages; };
     python = python311;
   };
 
@@ -47,5 +36,27 @@ buildNodejs {
       url = "https://github.com/nodejs/node/commit/d0a6b605fba6cd69a82e6f12ff0363eef8fe1ee9.patch";
       hash = "sha256-TfYal/PikRZHL6zpAlC3SmkYXCe+/8Gs83dLX/X/P/k=";
     })
+    # Remove unused `fdopen` in vendored zlib, which causes compilation failures with clang 18 on Darwin.
+    (fetchpatch2 {
+      url = "https://github.com/madler/zlib/commit/4bd9a71f3539b5ce47f0c67ab5e01f3196dc8ef9.patch?full_index=1";
+      extraPrefix = "deps/v8/third_party/zlib/";
+      stripLen = 1;
+      hash = "sha256-WVxsoEcJu0WBTyelNrVQFTZxJhnekQb1GrueeRBRdnY=";
+    })
+    # Backport V8 fixes for LLVM 19.
+    (fetchpatch2 {
+      url = "https://chromium.googlesource.com/v8/v8/+/182d9c05e78b1ddb1cb8242cd3628a7855a0336f%5E%21/?format=TEXT";
+      decode = "base64 -d";
+      extraPrefix = "deps/v8/";
+      stripLen = 1;
+      hash = "sha256-bDTwFbATPn5W4VifWz/SqaiigXYDWHq785C64VezuUE=";
+    })
+    (fetchpatch2 {
+      url = "https://chromium.googlesource.com/v8/v8/+/1a3ecc2483b2dba6ab9f7e9f8f4b60dbfef504b7%5E%21/?format=TEXT";
+      decode = "base64 -d";
+      extraPrefix = "deps/v8/";
+      stripLen = 1;
+      hash = "sha256-6y3aEqxNC4iTQEv1oewodJrhOHxjp5xZMq1P1QL94Rg=";
+    })
   ] ++ gypPatches;
 }
diff --git a/pkgs/development/web/nodejs/v20.nix b/pkgs/development/web/nodejs/v20.nix
index 4b0be19dad77..b147771e6660 100644
--- a/pkgs/development/web/nodejs/v20.nix
+++ b/pkgs/development/web/nodejs/v20.nix
@@ -48,5 +48,27 @@ buildNodejs {
       url = "https://github.com/nodejs/node/commit/0f7bdcc17fbc7098b89f238f4bd8ecad9367887b.patch?full_index=1";
       hash = "sha256-lXx6QyD2anlY9qAwjNMFM2VcHckBshghUF1NaMoaNl4=";
     })
+    # Remove unused `fdopen` in vendored zlib, which causes compilation failures with clang 18 on Darwin.
+    (fetchpatch2 {
+      url = "https://github.com/madler/zlib/commit/4bd9a71f3539b5ce47f0c67ab5e01f3196dc8ef9.patch?full_index=1";
+      extraPrefix = "deps/v8/third_party/zlib/";
+      stripLen = 1;
+      hash = "sha256-WVxsoEcJu0WBTyelNrVQFTZxJhnekQb1GrueeRBRdnY=";
+    })
+    # Backport V8 fixes for LLVM 19.
+    (fetchpatch2 {
+      url = "https://chromium.googlesource.com/v8/v8/+/182d9c05e78b1ddb1cb8242cd3628a7855a0336f%5E%21/?format=TEXT";
+      decode = "base64 -d";
+      extraPrefix = "deps/v8/";
+      stripLen = 1;
+      hash = "sha256-bDTwFbATPn5W4VifWz/SqaiigXYDWHq785C64VezuUE=";
+    })
+    (fetchpatch2 {
+      url = "https://chromium.googlesource.com/v8/v8/+/1a3ecc2483b2dba6ab9f7e9f8f4b60dbfef504b7%5E%21/?format=TEXT";
+      decode = "base64 -d";
+      extraPrefix = "deps/v8/";
+      stripLen = 1;
+      hash = "sha256-6y3aEqxNC4iTQEv1oewodJrhOHxjp5xZMq1P1QL94Rg=";
+    })
   ] ++ gypPatches;
 }
diff --git a/pkgs/os-specific/darwin/apple-source-releases/file_cmds/meson.build.in b/pkgs/os-specific/darwin/apple-source-releases/file_cmds/meson.build.in
index 7fc7ed7d901f..638742f978c2 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/file_cmds/meson.build.in
+++ b/pkgs/os-specific/darwin/apple-source-releases/file_cmds/meson.build.in
@@ -15,6 +15,7 @@ core_foundation = dependency('appleframeworks', modules : 'CoreFoundation')
 
 bzip2 = dependency('bzip2')
 xz = dependency('liblzma')
+libmd = dependency('libmd')
 libxo = dependency('libxo')
 zlib = dependency('zlib')
 
@@ -173,7 +174,7 @@ install_symlink(
 
 executable(
     'install-bin', # Meson reserves the name “install”, so use a different name and rename in install phase.
-    dependencies : [ copyfile ],
+    dependencies : [ copyfile, libmd ],
     install : true,
     sources: [
         'install/xinstall.c',
diff --git a/pkgs/os-specific/darwin/apple-source-releases/file_cmds/package.nix b/pkgs/os-specific/darwin/apple-source-releases/file_cmds/package.nix
index 93b578b1c008..584d2a312a60 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/file_cmds/package.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/file_cmds/package.nix
@@ -4,6 +4,7 @@
   bzip2,
   copyfile,
   less,
+  libmd,
   libutil,
   libxo,
   mkAppleDerivation,
@@ -104,6 +105,7 @@ mkAppleDerivation {
   buildInputs = [
     bzip2
     copyfile
+    libmd
     libutil
     libxo
     removefile
diff --git a/pkgs/servers/sql/mariadb/default.nix b/pkgs/servers/sql/mariadb/default.nix
index 76ce8d6b6dc9..a178e1fa28e4 100644
--- a/pkgs/servers/sql/mariadb/default.nix
+++ b/pkgs/servers/sql/mariadb/default.nix
@@ -14,7 +14,7 @@ let
     , bzip2, lz4, lzo, snappy, xz, zlib, zstd
     , cracklib, judy, libevent, libxml2
     , linux-pam, numactl
-    , fmt_8
+    , fmt_11
     , withStorageMroonga ? true, kytea, libsodium, msgpack, zeromq
     , withStorageRocks ? true
     , withEmbedded ? false
@@ -149,7 +149,7 @@ let
       ];
 
       buildInputs = common.buildInputs
-        ++ lib.optionals (lib.versionAtLeast common.version "10.7") [ fmt_8 ];
+        ++ lib.optionals (lib.versionAtLeast common.version "10.11") [ fmt_11 ];
 
       cmakeFlags = common.cmakeFlags ++ [
         "-DPLUGIN_AUTH_PAM=NO"
@@ -179,7 +179,7 @@ let
         ++ lib.optionals stdenv.hostPlatform.isLinux [ linux-pam ]
         ++ lib.optional (!stdenv.hostPlatform.isDarwin) mytopEnv
         ++ lib.optionals withStorageMroonga [ kytea libsodium msgpack zeromq ]
-        ++ lib.optionals (lib.versionAtLeast common.version "10.7") [ fmt_8 ];
+        ++ lib.optionals (lib.versionAtLeast common.version "10.11") [ fmt_11 ];
 
       propagatedBuildInputs = lib.optional withNuma numactl;
 
diff --git a/pkgs/stdenv/linux/default.nix b/pkgs/stdenv/linux/default.nix
index b8111f34e30a..e5a225f15838 100644
--- a/pkgs/stdenv/linux/default.nix
+++ b/pkgs/stdenv/linux/default.nix
@@ -385,6 +385,9 @@ in
             configureFlags = (a.configureFlags or []) ++ [
               "--with-native-system-header-dir=/include"
               "--with-build-sysroot=${lib.getDev self.stdenv.cc.libc}"
+              # Don't assume that `gettext` was built with iconv support, since we don't have
+              # our own `glibc` yet.
+              "--disable-nls"
             ];
 
             # This is a separate phase because gcc assembles its phase scripts
@@ -507,7 +510,7 @@ in
     overrides = self: super: rec {
       inherit (prevStage)
         ccWrapperStdenv
-        binutils coreutils gnugrep gettext
+        binutils coreutils gnugrep
         perl patchelf linuxHeaders gnum4 bison libidn2 libunistring libxcrypt;
         # We build a special copy of libgmp which doesn't use libstdc++, because
         # xgcc++'s libstdc++ references the bootstrap-files (which is what
diff --git a/pkgs/tools/misc/fontforge/default.nix b/pkgs/tools/misc/fontforge/default.nix
index 495a3dad8330..1eca97e7d7c7 100644
--- a/pkgs/tools/misc/fontforge/default.nix
+++ b/pkgs/tools/misc/fontforge/default.nix
@@ -29,6 +29,11 @@ stdenv.mkDerivation rec {
       url = "https://github.com/fontforge/fontforge/commit/216eb14b558df344b206bf82e2bdaf03a1f2f429.patch";
       hash = "sha256-aRnir09FSQMT50keoB7z6AyhWAVBxjSQsTRvBzeBuHU=";
     })
+    # Fixes translation compatibility with gettext 0.22
+    (fetchpatch {
+      url = "https://github.com/fontforge/fontforge/commit/55d58f87ab1440f628f2071a6f6cc7ef9626c641.patch";
+      hash = "sha256-rkYnKPXA8Ztvh9g0zjG2yTUCPd3lE1uqwvBuEd8+Oyw=";
+    })
 
     # https://github.com/fontforge/fontforge/pull/5423
     ./replace-distutils.patch
diff --git a/pkgs/tools/misc/torrenttools/default.nix b/pkgs/tools/misc/torrenttools/default.nix
index 6daa39dd7e73..3a634ec17373 100644
--- a/pkgs/tools/misc/torrenttools/default.nix
+++ b/pkgs/tools/misc/torrenttools/default.nix
@@ -54,6 +54,10 @@ stdenv.mkDerivation rec {
   ];
   sourceRoot = "torrenttools";
 
+  patches = [
+    ./fmt-9.patch
+  ];
+
   postUnpack = ''
     cp -pr cliprogress torrenttools/external/cliprogress
     cp -pr dottorrent torrenttools/external/dottorrent
diff --git a/pkgs/tools/misc/torrenttools/fmt-9.patch b/pkgs/tools/misc/torrenttools/fmt-9.patch
new file mode 100644
index 000000000000..5bdc666d4bd2
--- /dev/null
+++ b/pkgs/tools/misc/torrenttools/fmt-9.patch
@@ -0,0 +1,29 @@
+diff --git a/include/file_matcher.hpp b/include/file_matcher.hpp
+index c10c7be405..b67baec0ef 100644
+--- a/include/file_matcher.hpp
++++ b/include/file_matcher.hpp
+@@ -47,7 +47,7 @@
+         }
+ 
+         std::string error;
+-        std::string pattern = ".*.{}$"_format(extension);
++        std::string pattern = fmt::format(".*.{}$", extension);
+         file_include_list_.Add(pattern, &error);
+         file_include_list_empty_ = false;
+         Ensures(error.empty());
+@@ -62,7 +62,7 @@
+         }
+ 
+         std::string error;
+-        std::string pattern = ".*\\.{}$"_format(extension);
++        std::string pattern = fmt::format(".*\\.{}$", extension);
+         file_exclude_list_.Add(pattern, &error);
+         file_exclude_list_empty_ = false;
+         Ensures(error.empty());
+@@ -243,4 +243,4 @@
+ };
+ 
+ 
+-} // namespace torrenttools
+\ No newline at end of file
++} // namespace torrenttools
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 1446446b7d6c..dd2ad607389f 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -382,6 +382,7 @@ mapAliases {
   flutter316 = throw "flutter316 has been removed because it isn't updated anymore, and no packages in nixpkgs use it. If you still need it, use flutter.mkFlutter to get a custom version"; # Added 2024-10-05
   flutter322 = throw "flutter322 has been removed because it isn't updated anymore, and no packages in nixpkgs use it. If you still need it, use flutter.mkFlutter to get a custom version"; # Added 2024-10-05
   flutter323 = throw "flutter323 has been removed because it isn't updated anymore, and no packages in nixpkgs use it. If you still need it, use flutter.mkFlutter to get a custom version"; # Added 2024-10-05
+  fmt_8 = throw "fmt_8 has been removed as it is obsolete and was no longer used in the tree"; # Added 2024-11-12
   foldingathome = throw "'foldingathome' has been renamed to/replaced by 'fahclient'"; # Converted to throw 2024-10-17
   forgejo-actions-runner = forgejo-runner; # Added 2024-04-04
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index dbb7879616fc..10b1e3a191c5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -3895,7 +3895,7 @@ with pkgs;
     stdenv = llvmPackages_13.libcxxStdenv;
     libcxx = llvmPackages_13.libcxx;
     boost = boost178.override { inherit stdenv; };
-    fmt = fmt_8.override { inherit stdenv; };
+    fmt = fmt_9.override { inherit stdenv; };
     nanodbc_llvm = nanodbc.override { inherit stdenv; };
     avro-cpp_llvm = avro-cpp.override { inherit stdenv boost; };
     spdlog_llvm = spdlog.override { inherit stdenv fmt; };
@@ -6743,18 +6743,7 @@ with pkgs;
   libllvm = llvmPackages.libllvm;
   llvm-manpages = llvmPackages.llvm-manpages;
 
-  # Please remove all this logic when bumping to LLVM 19 and make this
-  # a simple alias.
-  llvmPackages = let
-    # This returns the minimum supported version for the platform. The
-    # assumption is that or any later version is good.
-    choose = platform: if platform.isDarwin then 16 else 18;
-    # We take the "max of the mins". Why? Since those are lower bounds of the
-    # supported version set, this is like intersecting those sets and then
-    # taking the min bound of that.
-    minSupported = toString (lib.trivial.max (choose stdenv.hostPlatform) (choose
-      stdenv.targetPlatform));
-  in pkgs.${"llvmPackages_${minSupported}"};
+  llvmPackages = llvmPackages_19;
 
   inherit (rec {
     llvmPackagesSet = recurseIntoAttrs (callPackages ../development/compilers/llvm { });
@@ -6923,7 +6912,7 @@ with pkgs;
 
   rust_1_82 = callPackage ../development/compilers/rust/1_82.nix {
     inherit (darwin.apple_sdk.frameworks) CoreFoundation Security SystemConfiguration;
-    llvm_18 = llvmPackages_18.libllvm;
+    llvm_19 = llvmPackages_19.libllvm;
   };
   rust = rust_1_82;
 
@@ -9199,7 +9188,7 @@ with pkgs;
   fltk = fltk13;
   fltk-minimal = fltk13-minimal;
 
-  inherit (callPackages ../development/libraries/fmt { }) fmt_8 fmt_9 fmt_10 fmt_11;
+  inherit (callPackages ../development/libraries/fmt { }) fmt_9 fmt_10 fmt_11;
 
   fmt = fmt_10;
 
@@ -11092,7 +11081,7 @@ with pkgs;
     harfbuzz = harfbuzzFull;
   };
 
-  termbench-pro = callPackage ../development/libraries/termbench-pro { fmt = fmt_8; };
+  termbench-pro = callPackage ../development/libraries/termbench-pro { fmt = fmt_11; };
 
   texpresso = callPackage ../tools/typesetting/tex/texpresso {
     texpresso-tectonic = callPackage ../tools/typesetting/tex/texpresso/tectonic.nix { };
@@ -16019,7 +16008,7 @@ with pkgs;
   };
 
   torrenttools = callPackage ../tools/misc/torrenttools {
-    fmt = fmt_8;
+    fmt = fmt_9;
   };
 
   tony = libsForQt5.callPackage ../applications/audio/tony { };
@@ -18404,7 +18393,7 @@ with pkgs;
   kmonad = haskellPackages.kmonad.bin;
 
   kompute = callPackage ../development/libraries/kompute {
-    fmt = fmt_8;
+    fmt = fmt_10;
   };
 
   # In general we only want keep the last three minor versions around that