RE: [BUG] Error adding 2+ files after init --shared on Windows with fscache

[Steven Kelly <stevek@metacase.com>]

On 2021-03-12 at 21:14:00, brian m.carlson wrote:
> On 2021-03-12 at 15:52:43, Steven Kelly wrote:
> > What did you do before the bug happened? (Steps to reproduce your
> issue)
> > Clean install of Git on Windows 10 using default options
> > git init --shared
> > echo x>x
> > echo y>y
> > git add -A
> >
> > What did you expect to happen? (Expected behavior)
> > The two files are added with no errors
> >
> > What happened instead? (Actual behavior)
> > error: unable to create temporary file: No such file or directory
> > error: y: failed to insert into database
> > error: unable to index file 'y'
> > fatal: adding files failed
> >
> > What's different between what you expected and what actually
> happened?
> > The add command fails with an error 'unable to create temporary file'
> >
> > Anything else you want to add:
> > If I omit --shared, there is no error
> > If there is only one file, there is no error
> > If the echo commands do not have characters, just adding a blank line,
> there is no error
> > If I turn off fscache, there is no error (git config --global core.fscache false)
> 
> Seeing this definitely makes me think this should be reported to the Git
> for Windows project (https://github.com/git-for-windows/git) because
> that's a nonstandard option that's specific to Windows.  I don't think
> anyone here (other, of course, than the Git for Windows folks) is
> familiar with how that option works and since it isn't part of core Git
> we wouldn't be able to fix it.

Thanks, duly reported: https://github.com/git-for-windows/git/issues/3110#issue-830551915
I note this bug does not occur in git version 2.9.3.windows.2 (2016) on Windows 10.0.18363.1316 with fscache
It seems to have existed since at least 2017: https://stackoverflow.com/a/44040893