The MERGE_HEAD ref is not available in the pre-merge-commit hook, but it is available in subsequent hooks prepare-commit-msg and commit-msg >From https://github.com/git/git/blob/master/builtin/merge.c#L843 : in prepare_to_commit() the call to write_merge_heads() is after run_commit_hook("pre-merge-commit") Can the write_merge_heads() call be moved up? At first glance it doesn't look like it would break anything.
