diff --git a/pkgs/build-support/fetchurl/mirrors.nix b/pkgs/build-support/fetchurl/mirrors.nix
index 5d7ebc7cd87b..ba78f36a17c0 100644
--- a/pkgs/build-support/fetchurl/mirrors.nix
+++ b/pkgs/build-support/fetchurl/mirrors.nix
@@ -53,10 +53,13 @@
   ];
 
   # GCC
+  # The commented out ones don't seem to be keeping up with the latest releases
+  # as of 2026-07-07 they don't have tarballs for 14.4 or 15.3
   gcc = [
-    "https://mirror.koddos.net/gcc/"
-    "https://bigsearcher.com/mirrors/gcc/"
-    "ftp://ftp.nluug.nl/mirror/languages/gcc/"
+    # "https://mirror.koddos.net/gcc/"
+    # "https://bigsearcher.com/mirrors/gcc/"
+    "https://mirrorservice.org/sites/sourceware.org/pub/gcc/"
+    # "ftp://ftp.nluug.nl/mirror/languages/gcc/"
     "ftp://ftp.fu-berlin.de/unix/languages/gcc/"
     "ftp://ftp.irisa.fr/pub/mirrors/gcc.gnu.org/gcc/"
     "ftp://gcc.gnu.org/pub/gcc/"
diff --git a/pkgs/by-name/ca/catch2_3/package.nix b/pkgs/by-name/ca/catch2_3/package.nix
index 4c931652b666..a00e75d4a29f 100644
--- a/pkgs/by-name/ca/catch2_3/package.nix
+++ b/pkgs/by-name/ca/catch2_3/package.nix
@@ -9,13 +9,13 @@
 
 stdenv.mkDerivation rec {
   pname = "catch2";
-  version = "3.15.0";
+  version = "3.15.2";
 
   src = fetchFromGitHub {
     owner = "catchorg";
     repo = "Catch2";
     tag = "v${version}";
-    hash = "sha256-1GBzS8jgJXb82BMMRuHWqszB1Xwg6wohmCuINWE7QoU=";
+    hash = "sha256-Fb8dnuaKQwLxYmGDZy38ZsCKk6RwE4PSidD1xmnb1rU=";
   };
 
   patches = lib.optionals stdenv.cc.isClang [
diff --git a/pkgs/by-name/re/redis/package.nix b/pkgs/by-name/re/redis/package.nix
index 98057ad86d3a..a46d70a2b3d8 100644
--- a/pkgs/by-name/re/redis/package.nix
+++ b/pkgs/by-name/re/redis/package.nix
@@ -77,8 +77,9 @@ stdenv.mkDerivation (finalAttrs: {
 
   env.NIX_LDFLAGS = lib.optionalString stdenv.hostPlatform.isFreeBSD "-lexecinfo";
 
-  # darwin currently lacks a pure `pgrep` which is extensively used here
-  doCheck = !stdenv.hostPlatform.isDarwin;
+  # Tests are in the `tests` passthru derivation: the suite is very large and some tests (e.g. memtests) are flaky.
+  doCheck = false;
+
   nativeCheckInputs = [
     which
     tcl
@@ -126,7 +127,10 @@ stdenv.mkDerivation (finalAttrs: {
   versionCheckProgram = "${placeholder "out"}/bin/redis-server";
 
   passthru = {
-    tests.redis = nixosTests.redis;
+    tests = {
+      redis = nixosTests.redis;
+      unitTests = finalAttrs.finalPackage.overrideAttrs { doCheck = true; };
+    };
     serverBin = "redis-server";
     updateScript = nix-update-script { };
   };
diff --git a/pkgs/by-name/va/valkey/package.nix b/pkgs/by-name/va/valkey/package.nix
index 4e0715702034..558f37808261 100644
--- a/pkgs/by-name/va/valkey/package.nix
+++ b/pkgs/by-name/va/valkey/package.nix
@@ -65,8 +65,9 @@ stdenv.mkDerivation (finalAttrs: {
 
   env.NIX_CFLAGS_COMPILE = toString (lib.optionals stdenv.cc.isClang [ "-std=c11" ]);
 
-  # darwin currently lacks a pure `pgrep` which is extensively used here
-  doCheck = !stdenv.hostPlatform.isDarwin;
+  # Tests are in the `tests` passthru derivation: the suite is very large and significantly slows down the build.
+  doCheck = false;
+
   nativeCheckInputs = [
     which
     tcl
@@ -109,7 +110,10 @@ stdenv.mkDerivation (finalAttrs: {
   '';
 
   passthru = {
-    tests.redis = nixosTests.redis;
+    tests = {
+      redis = nixosTests.redis;
+      unitTests = finalAttrs.finalPackage.overrideAttrs { doCheck = true; };
+    };
     serverBin = "valkey-server";
   };
 
diff --git a/pkgs/development/compilers/gcc/ng/default.nix b/pkgs/development/compilers/gcc/ng/default.nix
index c849367aa1fc..4eb9ca23b9b5 100644
--- a/pkgs/development/compilers/gcc/ng/default.nix
+++ b/pkgs/development/compilers/gcc/ng/default.nix
@@ -14,7 +14,7 @@
 }@packageSetArgs:
 let
   versions = {
-    "15.2.0".officialRelease.sha256 = "sha256-Q4/ZloJrDIJIWinaA6ctcdbjVBqD7HAt9Ccfb+Al0k4=";
+    "15.3.0".officialRelease.sha256 = "sha256-+lnBvu+JlfJ8TXHB3yJ1hxiTFdPm+v8btDBuYbDFMOs=";
   }
   // gccVersions;
 
diff --git a/pkgs/development/compilers/gcc/patches/14/gcc-darwin-remove-coreservices.patch b/pkgs/development/compilers/gcc/patches/14/gcc-darwin-remove-coreservices.patch
deleted file mode 100644
index 9d21a3c4c438..000000000000
--- a/pkgs/development/compilers/gcc/patches/14/gcc-darwin-remove-coreservices.patch
+++ /dev/null
@@ -1,39 +0,0 @@
-diff --git a/config/intlmacosx.m4 b/config/intlmacosx.m4
-index 3141bf8c5..7a31862b9 100644
---- a/config/intlmacosx.m4
-+++ b/config/intlmacosx.m4
-@@ -63,7 +63,7 @@ AC_DEFUN([gt_INTL_MACOSX],
-     dnl and we have to link it in explicitly, otherwise an exception
-     dnl NSInvalidArgumentException "unrecognized selector sent to instance"
-     dnl occurs.
--    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation -Wl,-framework -Wl,CoreServices"
-+    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation"
-   fi
-   AC_SUBST([INTL_MACOSX_LIBS])
- ])
-diff --git a/gcc/configure b/gcc/configure
-index 23da7d55d..8bd09364d 100755
---- a/gcc/configure
-+++ b/gcc/configure
-@@ -13932,7 +13932,7 @@ $as_echo "#define HAVE_CFLOCALECOPYPREFERREDLANGUAGES 1" >>confdefs.h
-   INTL_MACOSX_LIBS=
-   if test $gt_cv_func_CFPreferencesCopyAppValue = yes \
-      || test $gt_cv_func_CFLocaleCopyPreferredLanguages = yes; then
--                    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation -Wl,-framework -Wl,CoreServices"
-+                    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation"
-   fi
- 
- 
-diff --git a/libcpp/configure b/libcpp/configure
-index 32d6aaa30..592c33881 100755
---- a/libcpp/configure
-+++ b/libcpp/configure
-@@ -7570,7 +7570,7 @@ $as_echo "#define HAVE_CFLOCALECOPYPREFERREDLANGUAGES 1" >>confdefs.h
-   INTL_MACOSX_LIBS=
-   if test $gt_cv_func_CFPreferencesCopyAppValue = yes \
-      || test $gt_cv_func_CFLocaleCopyPreferredLanguages = yes; then
--                    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation -Wl,-framework -Wl,CoreServices"
-+                    INTL_MACOSX_LIBS="-Wl,-framework -Wl,CoreFoundation"
-   fi
- 
- 
diff --git a/pkgs/development/compilers/gcc/patches/14/libgcc-darwin-detection.patch b/pkgs/development/compilers/gcc/patches/14/libgcc-darwin-detection.patch
index c08706e8097f..772654cfd971 100644
--- a/pkgs/development/compilers/gcc/patches/14/libgcc-darwin-detection.patch
+++ b/pkgs/development/compilers/gcc/patches/14/libgcc-darwin-detection.patch
@@ -1,13 +1,12 @@
-diff --git a/libgcc/config.host b/libgcc/config.host
-index 7332903704..27a8b5bedb 100644
 --- a/libgcc/config.host
 +++ b/libgcc/config.host
-@@ -236,7 +236,7 @@
-   esac
-   tmake_file="$tmake_file t-slibgcc-darwin"
-   case ${host} in
+@@ -239,7 +239,7 @@ case ${host} in
+     x86_64-*-darwin2[0-2]*)
+       tmake_file="t-darwin-min-11 t-darwin-libgccs1 $tmake_file"
+       ;;
 -    *-*-darwin2*)
+-      tmake_file="t-darwin-min-11 $tmake_file"
 +    *-*-darwin2* | *-*-darwin)
-       tmake_file="t-darwin-min-11 $tmake_file"
++      tmake_file="t-darwin-min-11 t-darwin-libgccs1 $tmake_file"
        ;;
      *-*-darwin1[89]*)
diff --git a/pkgs/development/compilers/gcc/patches/15/aarch64-sve-rtx.patch b/pkgs/development/compilers/gcc/patches/15/aarch64-sve-rtx.patch
deleted file mode 100644
index 257c76d735da..000000000000
--- a/pkgs/development/compilers/gcc/patches/15/aarch64-sve-rtx.patch
+++ /dev/null
@@ -1,87 +0,0 @@
-Without the change `libhwy-1.3.0` ICEs when built for aarch64-linux as:
-https://github.com/NixOS/nixpkgs/pull/320616#issuecomment-3764400891
-
-Upstream report: http://gcc.gnu.org/PR120718
-Upstream fix: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d755aa03db0ad5b71ee7f39b09c92870789f2f00
-Fetched as:
-$ curl -L 'https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff_plain;h=d755aa03db0ad5b71ee7f39b09c92870789f2f00' > aarch64-sve-rtx.patch
-
-From: Richard Sandiford <richard.sandiford@arm.com>
-Date: Thu, 14 Aug 2025 16:56:50 +0000 (+0100)
-Subject: Remove MODE_COMPOSITE_P test from simplify_gen_subreg [PR120718]
-X-Git-Url: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff_plain;h=d755aa03db0ad5b71ee7f39b09c92870789f2f00
-
-Remove MODE_COMPOSITE_P test from simplify_gen_subreg [PR120718]
-
-simplify_gen_subreg rejected subregs of literal constants if
-MODE_COMPOSITE_P.  This was added by the fix for PR96648 in
-g:c0f772894b6b3cd8ed5c5dd09d0c7917f51cf70f.  Jakub said:
-
-  As for the simplify_gen_subreg change, I think it would be desirable
-  to just avoid creating SUBREGs of constants on all targets and for all
-  constants, if simplify_immed_subreg simplified, fine, otherwise punt,
-  but as we are late in GCC11 development, the patch instead guards this
-  behavior on MODE_COMPOSITE_P (outermode) - i.e. only conversions to
-  powerpc{,64,64le} double double long double - and only for the cases where
-  simplify_immed_subreg was called.
-
-I'm not sure about relaxing the codes further, since subregs might
-be wanted for CONST, SYMBOL_REF and LABEL_REF.  But removing the
-MODE_COMPOSITE_P is needed to fix PR120718, where we get an ICE
-from generating a subreg of a V2SI const_vector.
-
-Unlike the trunk version, this backport does not remove the
-VOIDmode test; see PR121501.
-
-gcc/
-	PR rtl-optimization/120718
-	* simplify-rtx.cc (simplify_context::simplify_gen_subreg):
-	Remove MODE_COMPOSITE_P condition.
-
-gcc/testsuite/
-	PR rtl-optimization/120718
-	* gcc.target/aarch64/sve/acle/general/pr120718.c: New test.
----
-
-diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
-index 88d31a71c05a..8d4cbf1371a3 100644
---- a/gcc/simplify-rtx.cc
-+++ b/gcc/simplify-rtx.cc
-@@ -8317,14 +8317,11 @@ simplify_context::simplify_gen_subreg (machine_mode outermode, rtx op,
- 
-   if (GET_CODE (op) == SUBREG
-       || GET_CODE (op) == CONCAT
--      || GET_MODE (op) == VOIDmode)
--    return NULL_RTX;
--
--  if (MODE_COMPOSITE_P (outermode)
--      && (CONST_SCALAR_INT_P (op)
--	  || CONST_DOUBLE_AS_FLOAT_P (op)
--	  || CONST_FIXED_P (op)
--	  || GET_CODE (op) == CONST_VECTOR))
-+      || GET_MODE (op) == VOIDmode
-+      || CONST_SCALAR_INT_P (op)
-+      || CONST_DOUBLE_AS_FLOAT_P (op)
-+      || CONST_FIXED_P (op)
-+      || GET_CODE (op) == CONST_VECTOR)
-     return NULL_RTX;
- 
-   if (validate_subreg (outermode, innermode, op, byte))
-diff --git a/gcc/testsuite/gcc.target/aarch64/sve/acle/general/pr120718.c b/gcc/testsuite/gcc.target/aarch64/sve/acle/general/pr120718.c
-new file mode 100644
-index 000000000000..9ca0938e36bf
---- /dev/null
-+++ b/gcc/testsuite/gcc.target/aarch64/sve/acle/general/pr120718.c
-@@ -0,0 +1,12 @@
-+/* { dg-options "-O2" } */
-+
-+#include <arm_sve.h>
-+typedef int __attribute__((vector_size(8))) v2si;
-+typedef struct { int x; int y; } A;
-+void bar(A a);
-+void foo()
-+{
-+    A a;
-+    *(v2si *)&a = (v2si){0, (int)svcntd_pat(SV_ALL)};
-+    bar(a);
-+}
diff --git a/pkgs/development/compilers/gcc/patches/15/libgcc-darwin-detection.patch b/pkgs/development/compilers/gcc/patches/15/libgcc-darwin-detection.patch
index 41e1c4c89869..20965f54be2b 100644
--- a/pkgs/development/compilers/gcc/patches/15/libgcc-darwin-detection.patch
+++ b/pkgs/development/compilers/gcc/patches/15/libgcc-darwin-detection.patch
@@ -1,9 +1,9 @@
 --- a/libgcc/config.host
 +++ b/libgcc/config.host
-@@ -239,8 +239,8 @@ case ${host} in
-     x86_64-*-darwin2[0-2]*)
-       tmake_file="t-darwin-min-11 t-darwin-libgccs1 $tmake_file"
-       ;;
+@@ -236,7 +236,7 @@
+   esac
+   tmake_file="$tmake_file t-slibgcc-darwin"
+   case ${host} in
 -    *-*-darwin2*)
 -      tmake_file="t-darwin-min-11 $tmake_file"
 +    *-*-darwin2* | *-*-darwin)
diff --git a/pkgs/development/compilers/gcc/patches/ada-cctools-as-detection-configure.patch b/pkgs/development/compilers/gcc/patches/ada-cctools-as-detection-configure.patch
deleted file mode 100644
index e6b5b3653322..000000000000
--- a/pkgs/development/compilers/gcc/patches/ada-cctools-as-detection-configure.patch
+++ /dev/null
@@ -1,33 +0,0 @@
-As originally implemented, the error message check
-described in the configure script
-breaks detection of Ada compiler support on x86_64-darwin,
-because the assembler in the version of cctools currently used
-unconditionally emits a deprecation message to stdout,
-with no way to disable it.
-
-Furthermore, GCC 3.4 was the minimum version needed to build GNAT
-as far back as GCC 4.4 (see the GCC git repo, tags/releases/gcc-4.4.0,
-gcc/doc/install.texi, lines 2052-2053 [1]);
-GCC 3.4 is newer than any of the broken GCC versions
-that the configure script works around
-(see the part of the comment in the configure script
-before the context in the patch below),
-and GCC 4.4 is older than any GCC that Nix currently packages (GCC 4.8).
-
-We therefore choose to not check for error messages,
-and just check for an error code.
-There's no harm in still checking for an object file being created, though.
-
-[1]: https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/doc/install.texi;h=6bdfbece981f7fb6c26da672d45e5d3ba7879c69;hb=b7fc996728085c0591ea7c5d0e1c84a8f6a29bd8#l2052
---- a/configure        2022-08-19 18:09:52.000000000 +1000
-+++ b/configure        2022-12-26 17:30:49.000000000 +1100
-@@ -5622,8 +5622,7 @@
- # Other compilers, like HP Tru64 UNIX cc, exit successfully when
- # given a .adb file, but produce no object file.  So we must check
- # if an object file was really produced to guard against this.
--errors=`(${CC} -c conftest.adb) 2>&1 || echo failure`
--if test x"$errors" = x && test -f conftest.$ac_objext; then
-+if ${CC} -c conftest.adb && test -f conftest.$ac_objext; then
-   acx_cv_cc_gcc_supports_ada=yes
- fi
- rm -f conftest.*
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
deleted file mode 100644
index 83aecff1a0df..000000000000
--- a/pkgs/development/compilers/gcc/patches/cfi_startproc-reorder-label-2.diff
+++ /dev/null
@@ -1,16 +0,0 @@
-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 cc0b5b47e9b4..5dbb716713c2 100644
--- a/pkgs/development/compilers/gcc/patches/default.nix
+++ b/pkgs/development/compilers/gcc/patches/default.nix
@@ -35,12 +35,6 @@ let
   is14 = majorVersion == "14";
   is13 = majorVersion == "13";
 
-  # 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 && buildIsHost && hostIsTarget;
-
   inherit (lib) optionals optional;
 in
 
@@ -82,7 +76,6 @@ optionals noSysDirs (
       "14" = [
         ./13/no-sys-dirs-riscv.patch
         ./13/mangle-NIX_STORE-in-__FILE__.patch
-        ./13/libsanitizer-fix-with-glibc-2.42.patch
       ];
       "13" = [
         ./13/no-sys-dirs-riscv.patch
@@ -108,67 +101,58 @@ optionals noSysDirs (
 # Needed to build llvm-18 and later
 # See https://github.com/NixOS/nixpkgs/pull/354107/commits/2de1b4b14e17f42ba8b4bf43a29347c91511e008
 ++ optional (!atLeast14) ./cfi_startproc-reorder-label-09-1.diff
-++ optional (atLeast14 && !canApplyIainsDarwinPatches) ./cfi_startproc-reorder-label-14-1.diff
+++ optional (atLeast14 && !targetPlatform.isDarwin) ./cfi_startproc-reorder-label-14-1.diff
 # c++tools: Don't check --enable-default-pie.
 # --enable-default-pie breaks bootstrap gcc otherwise, because libiberty.a is not found
 ++ optional (is14 || is15) ./c++tools-dont-check-enable-default-pie.patch
-# http://gcc.gnu.org/PR120718 backport (will be inclkuded in 15.3.0) to
-# fix `highway-1.3.0` ICE on aarch64-linux.
-++ optional is15 ./15/aarch64-sve-rtx.patch
 
 ## 2. Patches relevant on specific platforms ####################################
 
 ## Darwin
 
-# Fixes detection of Darwin on x86_64-darwin and aarch64-darwin. Otherwise, GCC uses a deployment target of 10.5, which crashes ld64.
-++ optional (
-  # this one would conflict with gcc-14-darwin-aarch64-support.patch
-  is14 && stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isx86_64
-) ../patches/14/libgcc-darwin-detection.patch
-++ optional (atLeast15 && stdenv.hostPlatform.isDarwin) ../patches/15/libgcc-darwin-detection.patch
-
-# Fix libgcc_s.1.dylib build on Darwin 11+ by not reexporting unwind symbols that don't exist
-++ optional (
-  atLeast15 && stdenv.hostPlatform.isDarwin
-) ../patches/15/libgcc-darwin-fix-reexport.patch
-
-# Fix detection of bootstrap compiler Ada support (cctools as) on Nix Darwin
-++ optional (stdenv.hostPlatform.isDarwin && langAda) ./ada-cctools-as-detection-configure.patch
-
-# Remove CoreServices on Darwin, as it is only needed for macOS SDK 14+
-++ optional (
-  atLeast14 && stdenv.hostPlatform.isDarwin && langAda
-) ../patches/14/gcc-darwin-remove-coreservices.patch
-
 # Here we apply patches by Iains (https://github.com/iains)
 # GitHub's "compare" API produces unstable diffs, so we resort to reusing
 # diffs from the Homebrew repo.
-++ optionals canApplyIainsDarwinPatches (
+++ optionals targetPlatform.isDarwin (
   {
+    "16" = [
+      # Fix libgcc_s.1.dylib build on Darwin 11+ by not reexporting unwind symbols that don't exist
+      ./15/libgcc-darwin-fix-reexport.patch
+      # Patches from https://github.com/iains/gcc-16-branch
+      (fetchpatch {
+        name = "gcc-16-darwin-aarch64-support.patch";
+        url = "https://raw.githubusercontent.com/Homebrew/homebrew-core/70e2a9e1d072fa3bc34cf41d97f4b65bede2b01e/Patches/gcc/gcc-16.1.0.diff";
+        hash = "sha256-dXfozKH//TRjAph7hUok7850hOdujTTi/iFM2HFA8fw=";
+      })
+      # Fixes detection of Darwin deployment target.
+      ./14/libgcc-darwin-detection.patch
+    ];
     "15" = [
-      # Patches from https://github.com/iains/gcc-15-branch/compare/releases/gcc-15..gcc-15.1-darwin-rc1
+      # Fix libgcc_s.1.dylib build on Darwin 11+ by not reexporting unwind symbols that don't exist
+      ./15/libgcc-darwin-fix-reexport.patch
+      # Patches from https://github.com/iains/gcc-15-branch
       (fetchpatch {
         name = "gcc-15-darwin-aarch64-support.patch";
-        url = "https://raw.githubusercontent.com/Homebrew/formula-patches/a25079204c1cb3d78ba9dd7dd22b8aecce7ce264/gcc/gcc-15.1.0.diff";
-        sha256 = "sha256-MJxSGv6LEP1sIM8cDqbmfUV7byV0bYgADeIBY/Teyu8=";
+        url = "https://raw.githubusercontent.com/Homebrew/homebrew-core/70e2a9e1d072fa3bc34cf41d97f4b65bede2b01e/Patches/gcc/gcc-15.3.0.diff";
+        hash = "sha256-PeAloBdUu+zRJlv86Z4x/FI8I7LiR5CJ3JlAJKs1iKU=";
       })
+      # Fixes detection of Darwin deployment target.
+      ./15/libgcc-darwin-detection.patch
     ];
     "14" = [
-      # Patches from https://github.com/iains/gcc-14-branch/compare/04696df09633baf97cdbbdd6e9929b9d472161d3..gcc-14.2-darwin-r2
+      # Patches from https://github.com/iains/gcc-14-branch
       (fetchpatch {
-        # There are no upstream release tags nor a static branch for 14.3.0 in https://github.com/iains/gcc-14-branch.
-        # aa4cd614456de65ee3417acb83c6cff0640144e9 is the merge base of https://github.com/iains/gcc-14-branch/tree/gcc-14-3-darwin-pre-0 and https://github.com/gcc-mirror/gcc/releases/tag/releases%2Fgcc-14.3.0
-        # 3e1d48d240f4aa5223c701b5c231c66f66ab1126 is the newest commit of https://github.com/iains/gcc-14-branch/tree/gcc-14-3-darwin-pre-0
         name = "gcc-14-darwin-aarch64-support.patch";
-        url = "https://github.com/iains/gcc-14-branch/compare/aa4cd614456de65ee3417acb83c6cff0640144e9..3e1d48d240f4aa5223c701b5c231c66f66ab1126.diff";
-        hash = "sha256-BSTSYnkBJBEm++mGerVVyaCUC4dUyXq0N1tqbk25bO4=";
+        url = "https://raw.githubusercontent.com/Homebrew/homebrew-core/d23df58f83aeb2c3f43bdcc277a9fac0bbe3e896/Patches/gcc/gcc-14.4.0.diff";
+        hash = "sha256-NU95q0xkP4wEi6XLJRWEhcMcL49gDuIHgZubC05QzRE=";
       })
+      ./14/libgcc-darwin-detection.patch
     ];
-    # Patches from https://github.com/iains/gcc-13-branch/compare/b71f1de6e9cf7181a288c0f39f9b1ef6580cf5c8..gcc-13-3-darwin
     "13" = [
+      # Patches from https://github.com/iains/gcc-13-branch
       (fetchpatch {
         name = "gcc-13-darwin-aarch64-support.patch";
-        url = "https://raw.githubusercontent.com/Homebrew/formula-patches/698885df7f624d0ce15bceb79a4d9760a473b502/gcc/gcc-13.4.0.diff";
+        url = "https://raw.githubusercontent.com/Homebrew/homebrew-core/d23df58f83aeb2c3f43bdcc277a9fac0bbe3e896/Patches/gcc/gcc-13.4.0.diff";
         hash = "sha256-xqkBDFYZ6fdowtqR3kV7bR8a4Cu11RDokSzGn1k3a1w=";
       })
     ];
@@ -176,21 +160,6 @@ optionals noSysDirs (
   .${majorVersion} or [ ]
 )
 
-# Use absolute path in GNAT dylib install names on Darwin
-++ optionals (stdenv.hostPlatform.isDarwin && langAda) (
-  {
-    "15" = [ ../patches/14/gnat-darwin-dylib-install-name-14.patch ];
-    "14" = [ ../patches/14/gnat-darwin-dylib-install-name-14.patch ];
-    # After the Iains patch, GCC 13 and 14 share the same patch.
-    "13" = [ ../patches/14/gnat-darwin-dylib-install-name-14.patch ];
-  }
-  .${majorVersion} or [ ]
-)
-
-++ optional (
-  langAda && is13 && canApplyIainsDarwinPatches
-) ./13/gnat13-aarch64-darwin-trampoline.patch
-
 ++ optional (targetPlatform.isWindows || targetPlatform.isCygwin) (fetchpatch {
   name = "libstdc-fix-compilation-in-freestanding-win32.patch";
   url = "https://inbox.sourceware.org/gcc-patches/20250922182808.2599390-2-corngood@gmail.com/raw";
diff --git a/pkgs/development/compilers/gcc/versions.nix b/pkgs/development/compilers/gcc/versions.nix
index ca6b2c91033d..2c91269d5d48 100644
--- a/pkgs/development/compilers/gcc/versions.nix
+++ b/pkgs/development/compilers/gcc/versions.nix
@@ -1,8 +1,8 @@
 let
   majorMinorToVersionMap = {
     "16" = "16.1.0";
-    "15" = "15.2.0";
-    "14" = "14.3.0";
+    "15" = "15.3.0";
+    "14" = "14.4.0";
     "13" = "13.4.0";
   };
 
@@ -15,8 +15,8 @@ let
       # 3 digits: releases (14.2.0)
       # 4 digits: snapshots (14.2.1.20250322)
       "16.1.0" = "sha256-UO+02Uwzl6/zsNYaWr10i03THZ0/Kre+BbFx02pRD3k=";
-      "15.2.0" = "sha256-Q4/ZloJrDIJIWinaA6ctcdbjVBqD7HAt9Ccfb+Al0k4=";
-      "14.3.0" = "sha256-4Nx3KXYlYxrI5Q+pL//v6Jmk63AlktpcMu8E4ik6yjo=";
+      "15.3.0" = "sha256-+lnBvu+JlfJ8TXHB3yJ1hxiTFdPm+v8btDBuYbDFMOs=";
+      "14.4.0" = "sha256-dStvVnvqyDFZx3p2gLExa914Rzi/+anQcBEsCdqQ9tk=";
       "13.4.0" = "sha256-nEzm27BAVo/cVFWIrAPFy8lajb8MeqSQFwhDr7WcqPU=";
     }
     ."${version}";
diff --git a/pkgs/development/compilers/gnat-bootstrap/default.nix b/pkgs/development/compilers/gnat-bootstrap/default.nix
index 650bf5b37e40..6a07f0502832 100644
--- a/pkgs/development/compilers/gnat-bootstrap/default.nix
+++ b/pkgs/development/compilers/gnat-bootstrap/default.nix
@@ -83,31 +83,28 @@ stdenv.mkDerivation (
         }
         .${stdenv.hostPlatform.system} or throwUnsupportedSystem;
         "15" = {
-          gccVersion = "15.2.0";
+          gccVersion = "15.3.0";
+          alireRevision = "1";
         }
         // {
           x86_64-darwin = {
-            alireRevision = "1";
             inherit url;
-            hash = "sha256-1YTqWsLBwNH/GBAtF5CL/YZHQvfE/3PE0LlLJ9HmjAg=";
-            upstreamTriplet = "x86_64-apple-darwin22.6.0";
+            hash = "sha256-VUEX89/ZXXxE0ks61unWoM0Oza6v4v3EwJs0vSDBwTQ=";
+            upstreamTriplet = "x86_64-apple-darwin24.6.0";
           };
           x86_64-linux = {
-            alireRevision = "1";
             inherit url;
-            hash = "sha256-b4hAg3ifoBRqgPxpfMYuOdunw7wzRTL/G5YGBO+im24=";
+            hash = "sha256-8CDxqAQW7zskadfdzMjJqzPN8GZ2qu/7NWvcQLDis1s=";
             upstreamTriplet = "x86_64-pc-linux-gnu";
           };
           aarch64-linux = {
-            alireRevision = "1";
             inherit url;
-            hash = "sha256-0V/VHqOSYQI6LmvpUIHy3zB6hI3dG0njOcDsrg8oZq8=";
+            hash = "sha256-cLLYWqdZuEZxV4ofd0GtO/+pQDMKs6TAOrAHw3DgI94=";
             upstreamTriplet = "aarch64-linux-gnu";
           };
           aarch64-darwin = {
-            alireRevision = "2-pre0";
-            url = "https://github.com/alire-project/GNAT-FSF-builds/releases/download/gnat-15.2.0-2-macos-pre0/gnat-${stdenv.hostPlatform.system}-${finalAttrs.version}.tar.gz";
-            hash = "sha256-4bFtsjixfXYc8wYOc+5iAbp1MmiIS1h1NcdKno2IdJg=";
+            inherit url;
+            hash = "sha256-WKwNQJEghnXQLexKHswn494b4sz+usvgYEIoNaedzCk=";
             upstreamTriplet = "aarch64-apple-darwin24.6.0";
           };
         }
diff --git a/pkgs/development/python-modules/backports-zstd/default.nix b/pkgs/development/python-modules/backports-zstd/default.nix
index db294f3527d7..0655b8d52181 100644
--- a/pkgs/development/python-modules/backports-zstd/default.nix
+++ b/pkgs/development/python-modules/backports-zstd/default.nix
@@ -9,7 +9,7 @@
 
 buildPythonPackage rec {
   pname = "backports-zstd";
-  version = "1.5.0";
+  version = "1.6.0";
   pyproject = true;
 
   src = fetchFromGitHub {
@@ -20,7 +20,7 @@ buildPythonPackage rec {
     postFetch = ''
       rm -r "$out/src/c/zstd"
     '';
-    hash = "sha256-0FGYh6o26oeovZ23VYKmmY2nNzDHXIKU8/lBqUxuGQw=";
+    hash = "sha256-UvQbyBROWRT7KfiYLPd7e/P98AaRqvJm/u17HeoOHnE=";
   };
 
   postPatch = ''
diff --git a/pkgs/development/python-modules/pikepdf/default.nix b/pkgs/development/python-modules/pikepdf/default.nix
index 3dc5a8698748..0dad049fcd08 100644
--- a/pkgs/development/python-modules/pikepdf/default.nix
+++ b/pkgs/development/python-modules/pikepdf/default.nix
@@ -27,22 +27,22 @@
   scikit-build-core,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "pikepdf";
-  version = "10.8.0";
+  version = "10.10.0";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "pikepdf";
     repo = "pikepdf";
-    tag = "v${version}";
+    tag = "v${finalAttrs.version}";
     # The content of .git_archival.txt is substituted upon tarball creation,
     # which creates indeterminism if master no longer points to the tag.
     # See https://github.com/jbarlow83/OCRmyPDF/issues/841
     postFetch = ''
       rm "$out/.git_archival.txt"
     '';
-    hash = "sha256-ih5QC6VVl7dGvamp3FRzahnpEDjdO8gGFNVX19Bu8LE=";
+    hash = "sha256-ZNynqKNmUO8wGoT3Ml2sS2kOGJD37JRaHzBV9igvoHw=";
   };
 
   patches = [
@@ -101,6 +101,6 @@ buildPythonPackage rec {
     description = "Read and write PDFs with Python, powered by qpdf";
     license = lib.licenses.mpl20;
     maintainers = with lib.maintainers; [ dotlambda ];
-    changelog = "https://github.com/pikepdf/pikepdf/blob/${src.tag}/docs/releasenotes/version${lib.versions.major version}.md";
+    changelog = "https://github.com/pikepdf/pikepdf/blob/${finalAttrs.src.tag}/docs/releasenotes/version${lib.versions.major finalAttrs.version}.md";
   };
-}
+})
diff --git a/pkgs/development/python-modules/pyturbojpeg/default.nix b/pkgs/development/python-modules/pyturbojpeg/default.nix
index d45067c67647..6845b412256f 100644
--- a/pkgs/development/python-modules/pyturbojpeg/default.nix
+++ b/pkgs/development/python-modules/pyturbojpeg/default.nix
@@ -11,16 +11,16 @@
   replaceVars,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "pyturbojpeg";
-  version = "2.3.0";
+  version = "2.4.0";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "lilohuang";
     repo = "PyTurboJPEG";
-    tag = "v${version}";
-    hash = "sha256-rMn5NmiwKhyj4U9kyyRf9ZheVnETpixZoL/AVlBlImQ=";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-LgUPcRBRjqKhg0SLaZiRG8/QoJxShSvAAmQsuHwfoZM=";
   };
 
   patches = [
@@ -46,10 +46,10 @@ buildPythonPackage rec {
   pythonImportsCheck = [ "turbojpeg" ];
 
   meta = {
-    changelog = "https://github.com/lilohuang/PyTurboJPEG/releases/tag/${src.tag}";
+    changelog = "https://github.com/lilohuang/PyTurboJPEG/releases/tag/${finalAttrs.src.tag}";
     description = "Python wrapper of libjpeg-turbo for decoding and encoding JPEG image";
     homepage = "https://github.com/lilohuang/PyTurboJPEG";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ dotlambda ];
   };
-}
+})
diff --git a/pkgs/development/python-modules/tzlocal/default.nix b/pkgs/development/python-modules/tzlocal/default.nix
index 16408d0710c0..fdd7bd269bce 100644
--- a/pkgs/development/python-modules/tzlocal/default.nix
+++ b/pkgs/development/python-modules/tzlocal/default.nix
@@ -2,44 +2,41 @@
   lib,
   stdenv,
   buildPythonPackage,
-  fetchPypi,
+  fetchFromGitHub,
   setuptools,
   pytest-mock,
   pytestCheckHook,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "tzlocal";
   version = "5.4.4"; # version needs to be compatible with APScheduler
-
   pyproject = true;
+  __structuredAttrs = true;
 
-  src = fetchPypi {
-    inherit pname version;
-    hash = "sha256-jbuGYIOGiKe2uk/tMdGN7fhCr7TUfKBQ1tiRwsFfO+Q=";
+  src = fetchFromGitHub {
+    owner = "regebro";
+    repo = "tzlocal";
+    tag = finalAttrs.version;
+    hash = "sha256-kZ3+YpmJJ7ZHKbEp5RELVnGtwAOJph19Wf32lwuokNM=";
   };
 
-  nativeBuildInputs = [ setuptools ];
+  build-system = [ setuptools ];
 
   nativeCheckInputs = [
     pytest-mock
     pytestCheckHook
   ];
 
-  disabledTests = [
-    "test_conflicting"
-    "test_noconflict"
-    "test_symlink_localtime"
-  ]
-  ++ lib.optional stdenv.hostPlatform.isDarwin "test_assert_tz_offset";
+  disabledTests = lib.optional stdenv.hostPlatform.isDarwin "test_assert_tz_offset";
 
   pythonImportsCheck = [ "tzlocal" ];
 
   meta = {
     description = "Tzinfo object for the local timezone";
     homepage = "https://github.com/regebro/tzlocal";
-    changelog = "https://github.com/regebro/tzlocal/blob/${version}/CHANGES.txt";
+    changelog = "https://github.com/regebro/tzlocal/blob/${finalAttrs.src.tag}/CHANGES.txt";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ dotlambda ];
   };
-}
+})
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gcc/10.nix b/pkgs/os-specific/linux/minimal-bootstrap/gcc/10.nix
index 25b06eb13f00..22db627fdb80 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gcc/10.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gcc/10.nix
@@ -43,10 +43,10 @@ let
     hash = "sha256-tnugOD736KhWNzTi6InvXsPDuJigHQD6CmhprYHGzgE=";
   };
 
-  mpcVersion = "1.3.1";
+  mpcVersion = "1.4.1";
   mpc = fetchurl {
-    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.gz";
-    hash = "sha256-q2QkkvXPiCt0qgy3MM1BCoHtzb7IlRg86TDnBsHHWbg=";
+    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.xz";
+    hash = "sha256-kSBM0y8WS9O3yZLUpqjOZRlRGq2rMPeLaYLQv41z6TE=";
   };
 in
 bash.runCommand "${pname}-${version}"
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gcc/glibc.nix b/pkgs/os-specific/linux/minimal-bootstrap/gcc/glibc.nix
index 3188453cea74..84429548ef45 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gcc/glibc.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gcc/glibc.nix
@@ -22,7 +22,7 @@
 }:
 let
   pname = "gcc";
-  version = "15.2.0";
+  version = "15.3.0";
   linkerName =
     {
       i686-linux = "ld-linux.so.2";
@@ -32,7 +32,7 @@ let
 
   src = fetchurl {
     url = "mirror://gnu/gcc/gcc-${version}/gcc-${version}.tar.xz";
-    hash = "sha256-Q4/ZloJrDIJIWinaA6ctcdbjVBqD7HAt9Ccfb+Al0k4=";
+    hash = "sha256-+lnBvu+JlfJ8TXHB3yJ1hxiTFdPm+v8btDBuYbDFMOs=";
   };
 
   gmpVersion = "6.3.0";
@@ -47,10 +47,10 @@ let
     hash = "sha256-tnugOD736KhWNzTi6InvXsPDuJigHQD6CmhprYHGzgE=";
   };
 
-  mpcVersion = "1.3.1";
+  mpcVersion = "1.4.1";
   mpc = fetchurl {
-    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.gz";
-    hash = "sha256-q2QkkvXPiCt0qgy3MM1BCoHtzb7IlRg86TDnBsHHWbg=";
+    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.xz";
+    hash = "sha256-kSBM0y8WS9O3yZLUpqjOZRlRGq2rMPeLaYLQv41z6TE=";
   };
 in
 bash.runCommand "${pname}-${version}"
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gcc/latest.nix b/pkgs/os-specific/linux/minimal-bootstrap/gcc/latest.nix
index 8abf382e17d6..0489f9ceb125 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gcc/latest.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gcc/latest.nix
@@ -21,11 +21,11 @@
 }:
 let
   pname = "gcc";
-  version = "15.2.0";
+  version = "15.3.0";
 
   src = fetchurl {
     url = "mirror://gnu/gcc/gcc-${version}/gcc-${version}.tar.xz";
-    hash = "sha256-Q4/ZloJrDIJIWinaA6ctcdbjVBqD7HAt9Ccfb+Al0k4=";
+    hash = "sha256-+lnBvu+JlfJ8TXHB3yJ1hxiTFdPm+v8btDBuYbDFMOs=";
   };
 
   gmpVersion = "6.3.0";
@@ -40,10 +40,10 @@ let
     hash = "sha256-tnugOD736KhWNzTi6InvXsPDuJigHQD6CmhprYHGzgE=";
   };
 
-  mpcVersion = "1.3.1";
+  mpcVersion = "1.4.1";
   mpc = fetchurl {
-    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.gz";
-    hash = "sha256-q2QkkvXPiCt0qgy3MM1BCoHtzb7IlRg86TDnBsHHWbg=";
+    url = "mirror://gnu/mpc/mpc-${mpcVersion}.tar.xz";
+    hash = "sha256-kSBM0y8WS9O3yZLUpqjOZRlRGq2rMPeLaYLQv41z6TE=";
   };
 in
 bash.runCommand "${pname}-${version}"
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gnumake/static.nix b/pkgs/os-specific/linux/minimal-bootstrap/gnumake/static.nix
index 65369e28fb64..29baaebafcfd 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gnumake/static.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gnumake/static.nix
@@ -70,7 +70,7 @@ bash.runCommand "${pname}-${version}"
 
     # Configure
     #
-    # Use std=gnu17 to avoid issue GCC 15.2.0 incompatibility.
+    # Use std=gnu17 to avoid issue GCC 15.3.0 incompatibility.
     # There is no newer release of gnumake available right now.
     bash ./configure \
       --prefix=$out \