Sorry for the long reply delay; the bug went away and only just showed up again. Here's the info you requested. I'm now running git 2.25.0. Showing the bug: % git show --patch df2f fatal: invalid commit position. commit-graph is likely corrupt commit df2f311c78b87d16509f352c66d7309957740711 (origin/feature/renderer) Author: [redacted] Date: Mon Jan 20 12:37:01 2020 -0500 WIP: add outline of back-end render web service Submodule packages/ngl f713ed5..7de8821: % Run "git commit-graph verify": doesn't detect any problem. % git commit-graph verify Verifying commits in commit graph: 100% (1/1), done. Verifying commits in commit graph: 100% (2/2), done. Verifying commits in commit graph: 100% (10/10), done. Verifying commits in commit graph: 100% (14/14), done. Verifying commits in commit graph: 100% (71/71), done. Verifying commits in commit graph: 100% (478/478), done You asked me to delete .git/objects/info/commit-graph -- I don't have such a file, but I do have a subdir "commit-graphs": % ls .git/objects/info/commit-graphs/ commit-graph-chain graph-e96da2872d5c5fc1c4e399f99b7800d08fcdd273.graph graph-4f5807bbdcba22f8fdc081c91205c40d40e99d38.graph graph-e9f543a1389f8f5d6e91c09caa6658a1905d00fe.graph graph-79f0f3bff07f7e7dda9d2438a30ef6483a2b531f.graph tmp_graph_GHI48b graph-83ce268fda98e26938ce702bb261e1719ff816ba.graph tmp_graph_Ypgl2f graph-93a966dc8be3040189367f047f5111e9f29c2d6c.graph After removing that subdir and running "git commit-graph write", I *do* have a .git/objects/info/commit-graph file. The bug is still present though! However, I do have a git submodule with its own .git/objects/info/commit-graphs; let's look into that. In the git submodule dir, "git commit-graph verify" succeeds with no errors (just like the parent). Deleted the .git/objects/info/commit-graphs subdir, regenerated with "git commit-graph write". Retest original problem: - Now the problem is fixed! So long story short: the corrupted git commit-graph was in a submodule. It does appear that "git commit-graph verify" failed to detect the corruption. Removing and regenerating fixes it. I do have the old git submodule's commit-graphs data in case it's useful. Let me know and I can send it along. On Mon, Jan 20, 2020 at 7:37 PM Derrick Stolee <stolee@xxxxxxxxx> wrote: > > On 1/20/2020 12:32 PM, Gary Oberbrunner wrote: > > I'm running git 2.24.1 on Linux/WSL, and sometimes git fails with this error: > > ``` > > % git diff --cached > > fatal: invalid commit position. commit-graph is likely corrupt > > ``` > > Usually that error goes away after I do a few more git operations, but > > I haven't been able to discern a pattern yet. It's not always with > > "diff", can be any git command as far as I can tell. > > Perhaps it started after I enabled the commit-graph stuff: > > ``` > > [core] > > editor = emacsclient -c -a \"\" > > preloadindex = true > > fscache = true > > autocrlf = false > > commitGraph = true > > writeCommitGraph = true > > ``` > > In fact, when I turn off `commitGraph`, the error goes away. But as I > > say, sometimes it goes away of its own accord. > > Disabling the featuere will definitely remove the error. Some commands may > also just not "visit" the corrupt commit. > > > Googling turns up almost nothing on this error. I have no idea if I've > > done something wrong to corrupt the commit graph, or if it's a git > > bug. If there's anything I can do to help debug it, I'd be happy to -- > > just let me know. > > Please run "git commit-graph verify" to see if that catches the > corruption. If not, then the verify feature is broken. > > Then, you can delete your .git/objects/info/commit-graph file > and rebuild it with "git commit-graph write". (If you have > fetch.writeCommitGraph enabled, then you may need to instead > delete the .git/objects/info/commit-graphs directory.) If that > process does not fix the problem, then there is definitely a bug > in the feature. At the moment, it may just be a flipped bit in > the file. > > Thanks, > -Stolee -- Gary
