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

Derrick Stolee [off-list ref] writes:

On 2/10/2021 7:18 AM, Filippo Valsorda wrote:

quoted

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

quoted

_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.

The mainline does have the BUG() statement, but it's really reflecting
bad data in the commit-graph file. That data was written by the internal
version and was not reset until you rewrote the file.

Thanks for digging, you two.  The above clearly explains the
symptom.

Thanks, but let me know if it reproduces again. The bug should be fixed
in ds/commit-graph-genno-fix [1], and I think the Google internal release
has been rolled back until that branch is included.

The topic has been cooking in 'next' since Feb 3rd, so jrnieder's
team would probably have already picked it up.  It would be in
'master', together with the ak/corrected-commit-date topic it builds
on, not in a very distant future (typically a topic cooks in 'next'
for a week, unless it is a trivial typofix, doc updates, that sort
of low-impact change).

Thanks.