I have used enableGitInfo = true in config for 1.5 year to lazily set the .Lastmod variable to the date of the last commit. It works when building locally with hugo server.
However, since Hugo 0.123 or so (and with latest 0.128.2), it has stopped working on Github Actions. .Lastmod gets set to the date of building, which is annoying because I hash it for guid in RSS feed, so all pages appear to be new at each rebuild.
I think at some point I changed actions/checkout@v2 to actions/checkout@v3 to fetch the source code from the Action. But v2 probably made a full clone, while v3 does a shallow clone by default. So, anyway I updated to