diff --git a/pkgs/applications/science/math/R/default.nix b/pkgs/applications/science/math/R/default.nix
index 83acfcfe9c37..580de87bdb23 100644
--- a/pkgs/applications/science/math/R/default.nix
+++ b/pkgs/applications/science/math/R/default.nix
@@ -8,15 +8,18 @@
 # R as of writing does not support outputting both .so and .a files; it outputs:
 #     --enable-R-static-lib conflicts with --enable-R-shlib and will be ignored
 , static ? false
+, testers
 }:
 
 assert (!blas.isILP64) && (!lapack.isILP64);
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "R";
   version = "4.2.2";
 
-  src = fetchurl {
+  src = let
+    inherit (finalAttrs) pname version;
+  in fetchurl {
     url = "https://cran.r-project.org/src/base/R-${lib.versions.major version}/${pname}-${version}.tar.gz";
     sha256 = "sha256-D/YrQuxRr6VxPK7nxP3noMRZQLo5vvjFyUh/7wyVPfU=";
   };
@@ -97,6 +100,8 @@ stdenv.mkDerivation rec {
 
   setupHook = ./setup-hook.sh;
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     homepage = "http://www.r-project.org/";
     description = "Free software environment for statistical computing and graphics";
@@ -121,8 +126,9 @@ stdenv.mkDerivation rec {
       user-defined recursive functions and input and output facilities.
     '';
 
+    pkgConfigModules = [ "libR" ];
     platforms = platforms.all;
 
     maintainers = with maintainers; [ jbedo ] ++ teams.sage.members;
   };
-}
+})
diff --git a/pkgs/development/libraries/ffmpeg/generic.nix b/pkgs/development/libraries/ffmpeg/generic.nix
index dceada0f7f8f..d0374c74901e 100644
--- a/pkgs/development/libraries/ffmpeg/generic.nix
+++ b/pkgs/development/libraries/ffmpeg/generic.nix
@@ -266,6 +266,10 @@
 , MediaToolbox
 , VideoDecodeAcceleration
 , VideoToolbox
+/*
+ *  Testing
+ */
+, testers
 }:
 
 /* Maintainer notes:
@@ -321,13 +325,13 @@ assert buildAvformat -> buildAvcodec && buildAvutil; # configure flag since 0.6
 assert buildPostproc -> buildAvutil;
 assert buildSwscale -> buildAvutil;
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "ffmpeg" + (if ffmpegVariant == "small" then "" else "-${ffmpegVariant}");
   inherit version;
 
   src = fetchgit {
     url = "https://git.ffmpeg.org/ffmpeg.git";
-    rev = "n${version}";
+    rev = "n${finalAttrs.version}";
     inherit sha256;
   };
 
@@ -522,7 +526,7 @@ stdenv.mkDerivation rec {
   # outputs where we don't want them. Patch the generated config.h to remove all
   # such references except for data.
   postConfigure = let
-    toStrip = lib.remove "data" outputs; # We want to keep references to the data dir.
+    toStrip = lib.remove "data" finalAttrs.outputs; # We want to keep references to the data dir.
   in
     "remove-references-to ${lib.concatStringsSep " " (map (o: "-t ${placeholder o}") toStrip)} config.h";
 
@@ -656,6 +660,8 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "A complete, cross-platform solution to record, convert and stream audio and video";
     homepage = "https://www.ffmpeg.org/";
@@ -671,7 +677,8 @@ stdenv.mkDerivation rec {
       ++ optional withGPL gpl2Plus
       ++ optional withGPLv3 gpl3Plus
       ++ optional withUnfree unfreeRedistributable;
+    pkgConfigModules = [ "libavutil" ];
     platforms = platforms.all;
     maintainers = with maintainers; [ atemu ];
   };
-}
+})
diff --git a/pkgs/development/libraries/hidapi/default.nix b/pkgs/development/libraries/hidapi/default.nix
index b29b64c2a757..e9bfe33e9f48 100644
--- a/pkgs/development/libraries/hidapi/default.nix
+++ b/pkgs/development/libraries/hidapi/default.nix
@@ -7,16 +7,17 @@
 , udev
 , Cocoa
 , IOKit
+, testers
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "hidapi";
   version = "0.12.0";
 
   src = fetchFromGitHub {
     owner = "libusb";
     repo = "hidapi";
-    rev = "${pname}-${version}";
+    rev = "${finalAttrs.pname}-${finalAttrs.version}";
     sha256 = "sha256-SMhlcB7LcViC6UFVYACjunxsGkvSOKC3mbLBH4XQSzM=";
   };
 
@@ -28,12 +29,20 @@ stdenv.mkDerivation rec {
 
   propagatedBuildInputs = lib.optionals stdenv.isDarwin [ Cocoa IOKit ];
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "Library for communicating with USB and Bluetooth HID devices";
     homepage = "https://github.com/libusb/hidapi";
     maintainers = with maintainers; [ prusnak ];
     # You can choose between GPLv3, BSD or HIDAPI license (even more liberal)
     license = with licenses; [ bsd3 /* or */ gpl3Only ] ;
+    pkgConfigModules = lib.optionals stdenv.isDarwin [
+      "hidapi"
+    ] ++ lib.optionals stdenv.isLinux [
+      "hidapi-hidraw"
+      "hidapi-libusb"
+    ];
     platforms = platforms.unix;
   };
-}
+})
diff --git a/pkgs/development/libraries/icu/63.nix b/pkgs/development/libraries/icu/63.nix
index 19838763f5b4..a83e2cd5f5eb 100644
--- a/pkgs/development/libraries/icu/63.nix
+++ b/pkgs/development/libraries/icu/63.nix
@@ -1,4 +1,6 @@
-{ stdenv, lib, fetchurl, fetchpatch, fixDarwinDylibNames, nativeBuildRoot, buildRootOnly ? false }:
+{ stdenv, lib, fetchurl, fetchpatch, fixDarwinDylibNames, nativeBuildRoot, testers
+, buildRootOnly ? false
+}:
 
 import ./base.nix {
   version = "63.1";
@@ -11,4 +13,4 @@ import ./base.nix {
     })
   ];
   patchFlags = [ "-p3" ];
-} { inherit stdenv lib fetchurl fixDarwinDylibNames nativeBuildRoot buildRootOnly; }
+} { inherit stdenv lib fetchurl fixDarwinDylibNames nativeBuildRoot testers buildRootOnly; }
diff --git a/pkgs/development/libraries/icu/base.nix b/pkgs/development/libraries/icu/base.nix
index a714e758bd88..c5e46fa4530d 100644
--- a/pkgs/development/libraries/icu/base.nix
+++ b/pkgs/development/libraries/icu/base.nix
@@ -2,6 +2,7 @@
 { stdenv, lib, fetchurl, fixDarwinDylibNames
   # Cross-compiled icu4c requires a build-root of a native compile
 , buildRootOnly ? false, nativeBuildRoot
+, testers
 }:
 
 let
@@ -45,6 +46,11 @@ let
       description = "Unicode and globalization support library";
       homepage = "https://icu.unicode.org/";
       maintainers = with maintainers; [ raskin ];
+      pkgConfigModules = [
+        "icu-i18n"
+        "icu-io"
+        "icu-uc"
+      ];
       platforms = platforms.all;
     };
   };
@@ -97,4 +103,6 @@ let
             then buildRootOnlyAttrs
           else realAttrs;
 in
-stdenv.mkDerivation attrs
+stdenv.mkDerivation (finalAttrs: attrs // {
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+})
diff --git a/pkgs/development/libraries/imlib2/default.nix b/pkgs/development/libraries/imlib2/default.nix
index 66092f436509..02707c750c06 100644
--- a/pkgs/development/libraries/imlib2/default.nix
+++ b/pkgs/development/libraries/imlib2/default.nix
@@ -21,17 +21,18 @@
 , fluxbox
 , enlightenment
 , xorg
+, testers
 }:
 
 let
   inherit (lib) optional optionals;
 in
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "imlib2";
   version = "1.9.1";
 
   src = fetchurl {
-    url = "mirror://sourceforge/enlightenment/${pname}-${version}.tar.xz";
+    url = "mirror://sourceforge/enlightenment/${finalAttrs.pname}-${finalAttrs.version}.tar.xz";
     hash = "sha256-SiJAOL//vl1NJQxE4F9O5a4k3P74OVsWd8cVxY92TUM=";
   };
 
@@ -69,6 +70,8 @@ stdenv.mkDerivation rec {
       enlightenment;
   };
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "Image manipulation library";
 
@@ -83,7 +86,8 @@ stdenv.mkDerivation rec {
     homepage = "https://docs.enlightenment.org/api/imlib2/html";
     changelog = "https://git.enlightenment.org/legacy/imlib2.git/plain/ChangeLog?h=v${version}";
     license = licenses.imlib2;
+    pkgConfigModules = [ "imlib2" ];
     platforms = platforms.unix;
     maintainers = with maintainers; [ spwhitt ];
   };
-}
+})
diff --git a/pkgs/development/libraries/libb2/default.nix b/pkgs/development/libraries/libb2/default.nix
index a461f5039aa7..9e507188aad3 100644
--- a/pkgs/development/libraries/libb2/default.nix
+++ b/pkgs/development/libraries/libb2/default.nix
@@ -4,16 +4,17 @@
 , autoreconfHook
 , libtool
 , pkg-config
+, testers
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "libb2";
   version = "0.98.1";
 
   src = fetchFromGitHub {
     owner = "BLAKE2";
     repo = "libb2";
-    rev = "refs/tags/v${version}";
+    rev = "refs/tags/v${finalAttrs.version}";
     sha256 = "0qj8aaqvfcavj1vj5asm4pqm03ap7q8x4c2fy83cqggvky0frgya";
   };
 
@@ -29,11 +30,14 @@ stdenv.mkDerivation rec {
 
   doCheck = true;
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "The BLAKE2 family of cryptographic hash functions";
     homepage = "https://blake2.net/";
+    pkgConfigModules = [ "libb2" ];
     platforms = platforms.all;
     maintainers = with maintainers; [ dfoxfranke dotlambda ];
     license = licenses.cc0;
   };
-}
+})
diff --git a/pkgs/development/libraries/openssl/default.nix b/pkgs/development/libraries/openssl/default.nix
index 488613fd489a..75ffe5ae06a6 100644
--- a/pkgs/development/libraries/openssl/default.nix
+++ b/pkgs/development/libraries/openssl/default.nix
@@ -10,6 +10,7 @@
 # path to openssl.cnf file. will be placed in $etc/etc/ssl/openssl.cnf to replace the default
 , conf ? null
 , removeReferencesTo
+, testers
 }:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
@@ -19,12 +20,12 @@
 
 let
   common = { version, sha256, patches ? [], withDocs ? false, extraMeta ? {} }:
-   stdenv.mkDerivation rec {
+   stdenv.mkDerivation (finalAttrs: {
     pname = "openssl";
     inherit version;
 
     src = fetchurl {
-      url = "https://www.openssl.org/source/${pname}-${version}.tar.gz";
+      url = "https://www.openssl.org/source/${finalAttrs.pname}-${version}.tar.gz";
       inherit sha256;
     };
 
@@ -204,13 +205,20 @@ let
       fi
     '';
 
+    passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
     meta = with lib; {
       homepage = "https://www.openssl.org/";
       description = "A cryptographic library that implements the SSL and TLS protocols";
       license = licenses.openssl;
+      pkgConfigModules = [
+        "libcrypto"
+        "libssl"
+        "openssl"
+      ];
       platforms = platforms.all;
     } // extraMeta;
-  };
+  });
 
 in {
 
diff --git a/pkgs/development/libraries/science/math/liblapack/default.nix b/pkgs/development/libraries/science/math/liblapack/default.nix
index b9563346ada4..3bf16057f835 100644
--- a/pkgs/development/libraries/science/math/liblapack/default.nix
+++ b/pkgs/development/libraries/science/math/liblapack/default.nix
@@ -6,16 +6,17 @@
 , shared ? true
 # Compile with ILP64 interface
 , blas64 ? false
+, testers
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "liblapack";
   version = "3.11";
 
   src = fetchFromGitHub {
     owner = "Reference-LAPACK";
     repo = "lapack";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     sha256 = "sha256-AYD78u70y8cY19hmM/aDjQEzxO8u9lPWhCFxRe5cqXI=";
   };
 
@@ -40,7 +41,7 @@ stdenv.mkDerivation rec {
 
   postInstall =  let
     canonicalExtension = if stdenv.hostPlatform.isLinux
-                       then "${stdenv.hostPlatform.extensions.sharedLibrary}.${lib.versions.major version}"
+                       then "${stdenv.hostPlatform.extensions.sharedLibrary}.${lib.versions.major finalAttrs.version}"
                        else stdenv.hostPlatform.extensions.sharedLibrary;
   in lib.optionalString blas64 ''
     ln -s $out/lib/liblapack64${canonicalExtension} $out/lib/liblapack${canonicalExtension}
@@ -65,15 +66,18 @@ stdenv.mkDerivation rec {
 
   checkPhase = ''
     runHook preCheck
-    ctest ${ctestArgs}
+    ctest ${finalAttrs.ctestArgs}
     runHook postCheck
   '';
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "Linear Algebra PACKage";
     homepage = "http://www.netlib.org/lapack/";
     maintainers = with maintainers; [ markuskowa ];
     license = licenses.bsd3;
+    pkgConfigModules = [ "lapack" ];
     platforms = platforms.all;
   };
-}
+})
diff --git a/pkgs/development/libraries/webkitgtk/default.nix b/pkgs/development/libraries/webkitgtk/default.nix
index 99ee89edcac3..fdefeb86a046 100644
--- a/pkgs/development/libraries/webkitgtk/default.nix
+++ b/pkgs/development/libraries/webkitgtk/default.nix
@@ -64,6 +64,7 @@
 , enableGeoLocation ? true
 , withLibsecret ? true
 , systemdSupport ? lib.meta.availableOn stdenv.hostPlatform systemd
+, testers
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -232,10 +233,17 @@ stdenv.mkDerivation (finalAttrs: {
 
   requiredSystemFeatures = [ "big-parallel" ];
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     description = "Web content rendering engine, GTK port";
     homepage = "https://webkitgtk.org/";
     license = licenses.bsd2;
+    pkgConfigModules = [
+      "javascriptcoregtk-4.0"
+      "webkit2gtk-4.0"
+      "webkit2gtk-web-extension-4.0"
+    ];
     platforms = platforms.linux ++ platforms.darwin;
     maintainers = teams.gnome.members;
     broken = stdenv.isDarwin;
diff --git a/pkgs/misc/jackaudio/default.nix b/pkgs/misc/jackaudio/default.nix
index 441f3ccb37f4..fce51aabd263 100644
--- a/pkgs/misc/jackaudio/default.nix
+++ b/pkgs/misc/jackaudio/default.nix
@@ -10,6 +10,8 @@
 
 # Extra options
 , prefix ? ""
+
+, testers
 }:
 
 with lib;
@@ -25,7 +27,7 @@ let
   optAlsaLib = if libOnly then null else shouldUsePkg alsa-lib;
   optLibopus = shouldUsePkg libopus;
 in
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "${prefix}jack2";
   version = "1.9.19";
 
@@ -63,11 +65,14 @@ stdenv.mkDerivation rec {
     wrapProgram $out/bin/jack_control --set PYTHONPATH $PYTHONPATH
   '');
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = {
     description = "JACK audio connection kit, version 2 with jackdbus";
     homepage = "https://jackaudio.org";
     license = licenses.gpl2Plus;
+    pkgConfigModules = [ "jack" ];
     platforms = platforms.unix;
     maintainers = with maintainers; [ goibhniu ];
   };
-}
+})
diff --git a/pkgs/misc/jackaudio/jack1.nix b/pkgs/misc/jackaudio/jack1.nix
index ba77e9c3c91a..4e7375a26916 100644
--- a/pkgs/misc/jackaudio/jack1.nix
+++ b/pkgs/misc/jackaudio/jack1.nix
@@ -2,6 +2,8 @@
 
 # Optional Dependencies
 , alsa-lib ? null, db ? null, libuuid ? null, libffado ? null, celt ? null
+
+, testers
 }:
 
 let
@@ -13,12 +15,12 @@ let
   optLibffado = shouldUsePkg libffado;
   optCelt = shouldUsePkg celt;
 in
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "jack1";
   version = "0.125.0";
 
   src = fetchurl {
-    url = "https://jackaudio.org/downloads/jack-audio-connection-kit-${version}.tar.gz";
+    url = "https://jackaudio.org/downloads/jack-audio-connection-kit-${finalAttrs.version}.tar.gz";
     sha256 = "0i6l25dmfk2ji2lrakqq9icnwjxklgcjzzk65dmsff91z2zva5rm";
   };
 
@@ -30,11 +32,14 @@ stdenv.mkDerivation rec {
   buildInputs = [ optAlsaLib optDb optLibffado optCelt ];
   propagatedBuildInputs = [ optLibuuid ];
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     broken = stdenv.isDarwin;
     description = "JACK audio connection kit";
     homepage = "https://jackaudio.org";
     license = with licenses; [ gpl2 lgpl21 ];
+    pkgConfigModules = [ "jack" ];
     platforms = platforms.unix;
   };
-}
+})
diff --git a/pkgs/tools/compression/brotli/default.nix b/pkgs/tools/compression/brotli/default.nix
index dfac5af0980b..3d15cbd395c4 100644
--- a/pkgs/tools/compression/brotli/default.nix
+++ b/pkgs/tools/compression/brotli/default.nix
@@ -4,18 +4,19 @@
 , cmake
 , fetchpatch
 , staticOnly ? stdenv.hostPlatform.isStatic
+, testers
 }:
 
 # ?TODO: there's also python lib in there
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "brotli";
   version = "1.0.9";
 
   src = fetchFromGitHub {
     owner = "google";
     repo = "brotli";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     sha256 = "z6Dhrabav1MDQ4rAcXaDv0aN+qOoh9cvoXZqEWBB13c=";
   };
 
@@ -55,6 +56,8 @@ stdenv.mkDerivation rec {
     cp ../docs/*.3 $out/share/man/man3/
   '';
 
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
+
   meta = with lib; {
     homepage = "https://github.com/google/brotli";
     description = "A generic-purpose lossless compression algorithm and tool";
@@ -72,6 +75,10 @@ stdenv.mkDerivation rec {
       '';
     license = licenses.mit;
     maintainers = with maintainers; [ freezeboy ];
+    pkgConfigModules = [
+      "libbrotlidec"
+      "libbrotlienc"
+    ];
     platforms = platforms.all;
   };
-}
+})