diff --git a/nix/pkgs/copybara.nix b/nix/pkgs/copybara.nix
index 91411602af..24b02c1acc 100644
--- a/nix/pkgs/copybara.nix
+++ b/nix/pkgs/copybara.nix
@@ -20,7 +20,7 @@ pkgs.buildBazelPackage rec {
   ];
 
   fetchAttrs = {
-    sha256 = "0id7y01fqc6br28ccayx2z3nz75kf5gvgzh0k8701vp4g6dgd5ym";
+    sha256 = "sha256:195av0bvgqgs7wwzx14yrrww582ijadvjdx82hx4911lp4jlbg8d";
     preHook = ''
       export COURSIER_CACHE="$(echo ''${NIX_BUILD_TOP}/tmp/coursier | sed -e 's,//,/,g')"
     '';
diff --git a/third_party/nixpkgs/pkgs/build-support/build-bazel-package/default.nix b/third_party/nixpkgs/pkgs/build-support/build-bazel-package/default.nix
index 3be72bd22c..103c55ee1f 100644
--- a/third_party/nixpkgs/pkgs/build-support/build-bazel-package/default.nix
+++ b/third_party/nixpkgs/pkgs/build-support/build-bazel-package/default.nix
@@ -126,7 +126,7 @@ in stdenv.mkDerivation (fBuildAttrs // {
       find $bazelOut/external -maxdepth 1 -type l | while read symlink; do
         name="$(basename "$symlink")"
         rm "$symlink"
-        test -f "$bazelOut/external/@$name.marker" && rm "$bazelOut/external/@$name.marker"
+        test -f "$bazelOut/external/@$name.marker" && rm "$bazelOut/external/@$name.marker" || exit 0
       done
 
       # Patching symlinks to remove build directory reference