Re: BUG: commit-reach.c:66: bad generation skip

On Mon, Feb 8, 2021 at 3:26 AM Derrick Stolee [off-list ref] wrote:

_This_ is interesting. I haven't heard of this problem happening
in a released version of Git.

I'm CC'ing Jonathan Nieder who recently saw this happening, but that
was on a newer version than 2.30.0 with a topic that is not part
of 2.30.0. But maybe the version shipped internally is versioned
without extra information on top of the latest tag? (I see your
@google.com email, which makes me think you have an internal version.)

Ah, the issue indeed first showed up as I was using the internal
version. I then installed mainline 2.30.0 to check that it reproduced
on the same local repository before reporting a bug.

To better understand your situation, could you please run the
following commands?

        git config --get-regexp graph
        git config features.experimental

I'm specifically looking for values of fetch.writeCommitGraph and
gc.writeCommitGraph.

fetch.writecommitgraph is enabled on the internal version.

$ git version
git version 2.30.0.478.g8a0d178c01-goog
$ git config --get-regexp graph
fetch.writecommitgraph true
$ git config features.experimental
$ ~/homebrew/bin/git version
git version 2.30.0
$ ~/homebrew/bin/git config --get-regexp graph
$ ~/homebrew/bin/git config features.experimental

I zipped up the repository and the worktree before running gc, so I can
run other commands for you if you need, but unfortunately I can't share
the archive, as it fetched from a private branch with security fixes.