google-cloud-cpp: fix paths in pkg-config files

pkgs/development/libraries/google-cloud-cpp/default.nix

@@ -42,6 +42,14 @@ stdenv.mkDerivation rec {
   postPatch = ''
     substituteInPlace external/googleapis/CMakeLists.txt \
       --replace "https://github.com/googleapis/googleapis/archive/\''${GOOGLE_CLOUD_CPP_GOOGLEAPIS_COMMIT_SHA}.tar.gz" "file://${googleapis}"
+
+    # https://github.com/googleapis/google-cloud-cpp/issues/8992
+    for file in external/googleapis/config.pc.in google/cloud/{,*/}config.pc.in; do
+      substituteInPlace "$file" \
+        --replace '$'{prefix}/@CMAKE_INSTALL_LIBDIR@ @CMAKE_INSTALL_FULL_LIBDIR@ \
+        --replace '$'{prefix}/@CMAKE_INSTALL_INCLUDEDIR@ @CMAKE_INSTALL_FULL_INCLUDEDIR@ \
+        --replace '$'{prefix}/@CMAKE_INSTALL_BINDIR@ @CMAKE_INSTALL_FULL_BINDIR@
+    done
   '';
 
   nativeBuildInputs = [