On Fri, Jul 23 2021, Atharva Raykar wrote: > On 22-Jul-2021, at 18:43, Tom Cook <tom.k.cook@xxxxxxxxx> wrote: >> On Wed, Jul 21, 2021 at 11:59 PM brian m. carlson >> <sandals@xxxxxxxxxxxxxxxxxxxx> wrote: >>> >>> On 2021-07-21 at 09:17:36, Tom Cook wrote: >>>> What did you do before the bug happened? (Steps to reproduce your issue) >>>> >>>> Add a git submodule to a git repository. >>>> Overlay-mount that submodule to another place in the filesystem. >>>> Attempt any git operation in the overlay-mounted path. >>> >>> I'm not sure about what you mean by an overlay-mount operation. Can you >>> provide some specific commands that we can run at a shell that reproduce >>> the issue? >>> -- >>> brian m. carlson (he/him or they/them) >>> Toronto, Ontario, CA >> >> The easiest way to reproduce it is this: >> >> $ mkdir test >> $ cd test >> $ echo "gitdir: /foo/bar" > .git >> $ git ls-remote https://github.com/torvalds/linux >> >> We happen to use overlay mounts in our build system in a way that maps >> a git submodule from one place to another so that its "gitdir" is >> invalid and then attempt a `git ls-remote` from that location which >> unexpectedly fails. But the above reproduces the problem well enough. > > 'ls-remote' needs a valid git directory for the case where the URL is not > explicitly supplied (to read the git config and learn the default remote). > > Making a special case for when an explicit URL is not given is not as > straightforward as it seems, because by the time 'ls-remote' even knows about > its arguments, it already takes a worktree prefix and sets up the environment, > for which a valid Git repository path is required. > > I am not too familiar with this area, and I don't know how feasible it is to > delay setting up the environment until after looking at the 'ls-remote' > arguments. At a cursory glance, it looks difficult to do without large > structural changes to the code. > > This might have been less of a problem with old-form submodules, where '.git' > was an actual directory, rather than a text file pointer [1], but newer > versions of Git discourage their usage. > > [1] https://git-scm.com/docs/gitsubmodules#_forms > > PS: we prefer bottom posting or inline replies :) > > --- > Pointers for others who might be interested in looking into this: > > The immediate cause of this seems to be 'setup.c:setup_gitdir_gently()' [2] > which calls 'setup_gitdir_gently_1()' with the 'die_on_error' argument set > to true. This function then calls 'read_gitfile_gently()' with the same flag, > which errors out when it runs 'is_git_directory()' [3], because the path in > the gitfile is not a valid repository. > > [2] https://github.com/git/git/blob/eb27b338a3e71c7c4079fbac8aeae3f8fbb5c687/setup.c#L1234 > [3] https://github.com/git/git/blob/eb27b338a3e71c7c4079fbac8aeae3f8fbb5c687/setup.c#L784-L799 The timing of this reply after [1] suggests that you may not have seen that patch that fixes this issue (sans Junio's outstanding comments on it). Perhaps your E-Mail client is forcing threading by subject only, not In-Reply-To chains? 1. https://lore.kernel.org/git/patch-1.1-fc26c46d39-20210722T140648Z-avarab@xxxxxxxxx/
