gbenchmark: fix paths in pkg-config file

pkgs/development/libraries/gbenchmark/default.nix

@@ -16,6 +16,11 @@ stdenv.mkDerivation rec {
   postPatch = ''
     cp -r ${gtest.src} googletest
     chmod -R u+w googletest
+
+    # https://github.com/google/benchmark/issues/1396
+    substituteInPlace cmake/benchmark.pc.in \
+      --replace '$'{prefix}/@CMAKE_INSTALL_LIBDIR@ @CMAKE_INSTALL_FULL_LIBDIR@ \
+      --replace '$'{prefix}/@CMAKE_INSTALL_INCLUDEDIR@ @CMAKE_INSTALL_FULL_INCLUDEDIR@
   '';
 
   doCheck = true;