vergen-git2 incorrectly emits rerun-if-changed=.git/

[gpanders]

vergen is emitting cargo:rerun-if-changed=.git/ which is causing our build script to be executed whenever any file under the .git directory changes. This is causing excessive rebuilds.

According to the docs, vergen should be emitting rerun-if-changed=.git/HEAD and rerun-if-changed=.git/<ref>, where <ref> is the name of the ref that HEAD resolves to. In my case, instead of .git/<ref> I see only .git/.

This appears to be due to this line in add_rerun_if_changed

vergen/vergen-git2/src/git2/mod.rs

Line 522 in 4d78e16

cargo_rerun_if_changed.push(format!("{}", ref_path.display()));

This should instead be path.display(): ref_path points to the .git directory itself.