Recover the complicated situation after my bad merge

I made a mistake merge.  Reverting it in c778945806 undid the state
on master, but now I realize it crippled the git merge mechanism.
As the merge contained a mix of commits from `master..staging-next`
and other commits from `staging-next..staging`, it got the
`staging-next` branch into a state that was difficult to recover.

I reconstructed the "desired" state of staging-next tree by:
 - checking out the last commit of the problematic range: 4effe769e2
 - `git rebase -i --preserve-merges a8a018ddc0` - dropping the mistaken
   merge commit and its revert from that range (while keeping
   reapplication from 4effe769e2)
 - merging the last unaffected staging-next commit (803ca85c20)
 - fortunately no other commits have been pushed to staging-next yet
 - applying a diff on staging-next to get it into that state

pkgs/tools/compression/brotli/default.nix

@@ -4,13 +4,13 @@
 
 stdenv.mkDerivation rec {
   pname = "brotli";
-  version = "1.0.7";
+  version = "1.0.9";
 
   src = fetchFromGitHub {
     owner = "google";
     repo = "brotli";
     rev = "v" + version;
-    sha256 = "1811b55wdfg4kbsjcgh1kc938g118jpvif97ilgrmbls25dfpvvw";
+    sha256 = "z6Dhrabav1MDQ4rAcXaDv0aN+qOoh9cvoXZqEWBB13c=";
   };
 
   nativeBuildInputs = [ cmake ];
@@ -32,7 +32,14 @@ stdenv.mkDerivation rec {
 
   # This breaks on Darwin because our cmake hook tries to make a build folder
   # and the wonderful bazel BUILD file is already there (yay case-insensitivity?)
-  prePatch = "rm BUILD";
+  prePatch = ''
+      rm BUILD
+
+      # Upstream fixed this reference to runtime-path after the release
+      # and with this references g++ complains about invalid option -R
+      sed -i 's/ -R''${libdir}//' scripts/libbrotli*.pc.in
+      cat scripts/libbrotli*.pc.in
+    '';
 
   # Don't bother with "man" output for now,
   # it currently only makes the manpages hard to use.