Merge pull request #199978 from amjoseph-nixpkgs/pr/boehmgc/powerpc64le

boehmgc: disable SOFT_VDB on powerpc64le for version 8.2.2

pkgs/development/libraries/boehm-gc/default.nix

@@ -30,6 +30,21 @@ stdenv.mkDerivation (finalAttrs: {
   ++ lib.optional enableMmap "--enable-mmap"
   ++ lib.optional enableLargeConfig "--enable-large-config";
 
+  # This stanza can be dropped when a release fixes this issue:
+  #   https://github.com/ivmai/bdwgc/issues/376
+  # The version is checked with == instead of versionAtLeast so we
+  # don't forget to disable the fix (and if the next release does
+  # not fix the problem the test failure will be a reminder to
+  # extend the set of versions requiring the workaround).
+  makeFlags = if (stdenv.hostPlatform.isPower64 &&
+                  finalAttrs.version == "8.2.2")
+    then [
+      # do not use /proc primitives to track dirty bits; see:
+      # https://github.com/ivmai/bdwgc/issues/479#issuecomment-1279687537
+      # https://github.com/ivmai/bdwgc/blob/54522af853de28f45195044dadfd795c4e5942aa/include/private/gcconfig.h#L741
+      "CFLAGS_EXTRA=-DNO_SOFT_VDB"
+    ] else null;
+
   # `gctest` fails under emulation on aarch64-darwin
   doCheck = !(stdenv.isDarwin && stdenv.isx86_64);