Hello again,
I wondered what is happening about this issue?
This continues to cause problems, especially now that Mac is using Git
2.21 (without AFAICT any way to revert to 2.17).
The most recent case was last night, after a Work In Progress branch (that
is, it was not used by any production code) in a submodule was pushed, but
updates for at least one of the submodules wasn't pushed. Three different
Mac autobuild jobs broke because of this error and had to be restarted.
On Mon, 18 May 2020 11:20:57 +0200, Yngve N. Pettersen <yngve@xxxxxxxxxxx>
wrote:
Hello all,
A while back I reported an issue to the Windows Git project
<https://github.com/git-for-windows/git/issues/2218> that I observed in
Git for Windows 2.21.
The error message "Server does not allow request for unadvertised
object" is reported when a commit updating a submodule pointer points to
a commit that does not exist in the repository for that submodule, even
if later commits in the branch points to a commit that do exist in the
submodule repo.
This circumstance can easily occur if a developer (e.g)
* interactively rebases a branch "foo" in the submodule (e.g to
integrate commits from another branch before a larger rebase)
* commits the resulting submodule pointer "A" in the branch to the
parent repo
* then do further rebasing in the submodule, e.g to move up on top of
the "bar" branch
* commits that pointer "B" to the parent repo
* forgets to squash the history in the parent repo
* pushes the updated submodule "foo" branch to the online repo. (NOTE:
"B" is pushed, not "A")
* pushes the parent module branch to its online repo
When the parent repo is pulled by another developer, or an autobuild
system, the fetch operation fails with the message "Server does not
allow request for unadvertised object". A second fetch will complete
successfully.
IMO this kind of check should only happen if a commit with pointer to a
missing submodule is actively checked out. At most the above message
should be a warning, not a fatal error.
For manual fetch operations this is mostly a nuisance, but for
autobuilders this breaks the update operation, and the entire build
operation fails. That is unacceptable behavior in an automatic system
(errors if it breaks the checkout, yes; issues that are not relevant to
the actual checkout, no).
This issue prevents upgrading past 2.17 (since 2.18 and 2.19 had other
blocking issues, and 2.20 apparently introduced this issue). I have not
tested 2.22+ since I have not noticed any changelog messages that seem
related.
A test case can be found in issue 2218, linked above.
For reference, we do have a server-side git hook that verifies that
submodule pointers for the production branch is correct and exists in
the submodule's repo, and also is on branches that follows certain
naming conventions.
As an aside, I think this kind of error message would be have been
better suited as either a client-side push check, to prevent pushes of
references to such missing commits (Smartgit seems to have something
like it, but I think it only checks for the current branch in the
submodule, not all submodule reference commits). Alternatively, there
could be a check of this server-side.
Related to this, but not as problematic, just irritating, and also seen
in 2.17, is a message "warning: Submodule in commit deadbee at path:
'(NULL)' collides with a submodule named the same. Skipping it." I think
it is related to recreating a git modules file on a different branch.
--
Sincerely,
Yngve N. Pettersen
Vivaldi Technologies AS
