git push recurse.submodules behavior changed in 2.13

git push recurse.submodules behavior changed in 2.13

[John Shahid]

Hi all,

It looks like the git push recurse-submodules behavior has changed.
Currently with 2.13 you cannot run "git push
--recurse-submodules=on-demand" if the parent repo is on a different
branch than the sub repos, e.g. parent repo is on "develop" and
sub-repo on "master". I created a test that can be found here [1].

A bisect shows that the change to propagate refspec [2] to the
submodules is the culprit. imho this is an undesired change in
behavior. I looked at the code but couldn't see an easy way to fix
this issue without breaking the feature mentioned above. The only
option I can think of is to control the refspec propagation behavior
using a flag, e.g. "--propagate-refspecs" or add another
recurse-submodules option, e.g. "--recurse-submodules=propagate"

What do you all think ?

[1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
[2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780

Re: git push recurse.submodules behavior changed in 2.13

[Junio C Hamano]

John Shahid <jvshahid@gmail.com> writes:

> It looks like the git push recurse-submodules behavior has changed.
> Currently with 2.13 you cannot run "git push
> --recurse-submodules=on-demand" if the parent repo is on a different
> branch than the sub repos, e.g. parent repo is on "develop" and
> sub-repo on "master". I created a test that can be found here [1].
>
> A bisect shows that the change to propagate refspec [2] to the
> submodules is the culprit. imho this is an undesired change in
> behavior. I looked at the code but couldn't see an easy way to fix
> this issue without breaking the feature mentioned above. The only
> option I can think of is to control the refspec propagation behavior
> using a flag, e.g. "--propagate-refspecs" or add another
> recurse-submodules option, e.g. "--recurse-submodules=propagate"
>
> What do you all think ?
>
> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780

Brandon?  I cannot quite tell from the report what "has changed"
refers to, what failures "you cannot run" gets, and if that is a
desirable thing to do (i.e. if letting the user run it in such a
configuration would somehow break things, actively erroring out may
be a deliberate change) or not (i.e. an unintended regression).

Re: git push recurse.submodules behavior changed in 2.13

[Stefan Beller]

On Sun, May 28, 2017 at 7:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
> John Shahid <jvshahid@gmail.com> writes:
>
>> It looks like the git push recurse-submodules behavior has changed.
>> Currently with 2.13 you cannot run "git push
>> --recurse-submodules=on-demand" if the parent repo is on a different
>> branch than the sub repos, e.g. parent repo is on "develop" and
>> sub-repo on "master". I created a test that can be found here [1].
>>
>> A bisect shows that the change to propagate refspec [2] to the
>> submodules is the culprit. imho this is an undesired change in
>> behavior. I looked at the code but couldn't see an easy way to fix
>> this issue without breaking the feature mentioned above. The only
>> option I can think of is to control the refspec propagation behavior
>> using a flag, e.g. "--propagate-refspecs" or add another
>> recurse-submodules option, e.g. "--recurse-submodules=propagate"
>>
>> What do you all think ?
>>
>> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
>> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
>
> Brandon?  I cannot quite tell from the report what "has changed"
> refers to, what failures "you cannot run" gets, and if that is a
> desirable thing to do (i.e. if letting the user run it in such a
> configuration would somehow break things, actively erroring out may
> be a deliberate change) or not (i.e. an unintended regression).
>

Before the refspec was passed down into the submodules,
we'd just invoke "git push" in the submodule assuming the user
setup a remote tracking branch and a push strategy such that
"git push" would do the right thing.
And because the submodule is configured independently, it
doesn't matter which branch you're on in the superproject.

Looking at the test[1], you run "git push --recurse-submodules"
without any remote/branch that was called out in the commit
message[2] to not have changed. Is that understanding correct?

Looking at the test cases of [2] we did not test for explicit
"still works with no args given", though one could have expected
we'd have a test for that already. :/

Thanks,
Stefan

Re: git push recurse.submodules behavior changed in 2.13

[John Shahid]

Junio, sorry for the poor report. I totally forgot to describe the
behavior that i'm currently getting vs what i expect.

Expected behavior:

We have a parent repo on a branch called "develop" and a submodule on
a branch called "master". Prior to git version 2.13 if we had an
unpushed commit in the submodule and ran "git push origin develop
--recurse-submodules=on-demand" git would happily push the develop
branch of the parent repo and the master branch of the submodule,
e.g.:

> Pushing submodule 'sub'
> Counting objects: 2, done.
> Delta compression using up to 4 threads.
> Compressing objects: 100% (2/2), done.
> Writing objects: 100% (2/2), 242 bytes | 0 bytes/s, done.
> Total 2 (delta 0), reused 0 (delta 0)
> To /home/jvshahid/codez/git/t/trash directory.t9904-diff-branch-submodule-push/sub.git
>    3cd2129..69cbc06  master -> master
> Counting objects: 2, done.
> Delta compression using up to 4 threads.
> Compressing objects: 100% (2/2), done.
> Writing objects: 100% (2/2), 283 bytes | 0 bytes/s, done.
> Total 2 (delta 0), reused 0 (delta 0)
> To ../pub.git
>    7ff6fca..945bc12  develop -> develop
> ok 2 - push if submodule has is on a different branch

Actual behavior:

After the change mentioned in my previous email, git would propagate
the refspec from the parent repo to the submodule, i.e. it would try
to push a branch called "develop" in the submodule which would error
since no branch with that name exist in the submodule. Here is a
sample output with git v2.13.0:

> pushing to ref refs/heads/develop:refs/heads/develop
> pushging to remote origin
> fatal: src refspec 'refs/heads/develop' must name a ref
> fatal: process for submodule 'sub' failed
> fatal: The remote end hung up unexpectedly

I hope this clarifies my bug report.

Stefan, one little correction. I don't think the commit called out
this behavior. The commit message was talking about unconfigured
remotes (i.e. pushing to a url or local path) to not propagate the
refspec and preserve the current behavior. Judging from the code and a
test case that I wrote, this behavior is working as expected. That is,
git won't propagate the refspec.

Cheers,

JS

On Mon, May 29, 2017 at 12:20 AM, Stefan Beller <sbeller@google.com> wrote:
> On Sun, May 28, 2017 at 7:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> John Shahid <jvshahid@gmail.com> writes:
>>
>>> It looks like the git push recurse-submodules behavior has changed.
>>> Currently with 2.13 you cannot run "git push
>>> --recurse-submodules=on-demand" if the parent repo is on a different
>>> branch than the sub repos, e.g. parent repo is on "develop" and
>>> sub-repo on "master". I created a test that can be found here [1].
>>>
>>> A bisect shows that the change to propagate refspec [2] to the
>>> submodules is the culprit. imho this is an undesired change in
>>> behavior. I looked at the code but couldn't see an easy way to fix
>>> this issue without breaking the feature mentioned above. The only
>>> option I can think of is to control the refspec propagation behavior
>>> using a flag, e.g. "--propagate-refspecs" or add another
>>> recurse-submodules option, e.g. "--recurse-submodules=propagate"
>>>
>>> What do you all think ?
>>>
>>> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
>>> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
>>
>> Brandon?  I cannot quite tell from the report what "has changed"
>> refers to, what failures "you cannot run" gets, and if that is a
>> desirable thing to do (i.e. if letting the user run it in such a
>> configuration would somehow break things, actively erroring out may
>> be a deliberate change) or not (i.e. an unintended regression).
>>
>
> Before the refspec was passed down into the submodules,
> we'd just invoke "git push" in the submodule assuming the user
> setup a remote tracking branch and a push strategy such that
> "git push" would do the right thing.
> And because the submodule is configured independently, it
> doesn't matter which branch you're on in the superproject.
>
> Looking at the test[1], you run "git push --recurse-submodules"
> without any remote/branch that was called out in the commit
> message[2] to not have changed. Is that understanding correct?
>
> Looking at the test cases of [2] we did not test for explicit
> "still works with no args given", though one could have expected
> we'd have a test for that already. :/
>
> Thanks,
> Stefan

Re: git push recurse.submodules behavior changed in 2.13

[Brandon Williams]

On 05/30, John Shahid wrote:
> Junio, sorry for the poor report. I totally forgot to describe the
> behavior that i'm currently getting vs what i expect.
> 
> Expected behavior:
> 
> We have a parent repo on a branch called "develop" and a submodule on
> a branch called "master". Prior to git version 2.13 if we had an
> unpushed commit in the submodule and ran "git push origin develop
> --recurse-submodules=on-demand" git would happily push the develop
> branch of the parent repo and the master branch of the submodule,
> e.g.:

Yeah my patches would definitely break that kind of workflow because
they assumed that if you actually provided a refspec + --recurse that
you would want it propagated down.  When developing those patches I was
trying to avoid needing to add an additional flag to do the propagation
but given people were already relying on this behavior it looks like
that may be the only course of action.

> 
> > Pushing submodule 'sub'
> > Counting objects: 2, done.
> > Delta compression using up to 4 threads.
> > Compressing objects: 100% (2/2), done.
> > Writing objects: 100% (2/2), 242 bytes | 0 bytes/s, done.
> > Total 2 (delta 0), reused 0 (delta 0)
> > To /home/jvshahid/codez/git/t/trash directory.t9904-diff-branch-submodule-push/sub.git
> >    3cd2129..69cbc06  master -> master
> > Counting objects: 2, done.
> > Delta compression using up to 4 threads.
> > Compressing objects: 100% (2/2), done.
> > Writing objects: 100% (2/2), 283 bytes | 0 bytes/s, done.
> > Total 2 (delta 0), reused 0 (delta 0)
> > To ../pub.git
> >    7ff6fca..945bc12  develop -> develop
> > ok 2 - push if submodule has is on a different branch
> 
> Actual behavior:
> 
> After the change mentioned in my previous email, git would propagate
> the refspec from the parent repo to the submodule, i.e. it would try
> to push a branch called "develop" in the submodule which would error
> since no branch with that name exist in the submodule. Here is a
> sample output with git v2.13.0:
> 
> > pushing to ref refs/heads/develop:refs/heads/develop
> > pushging to remote origin
> > fatal: src refspec 'refs/heads/develop' must name a ref
> > fatal: process for submodule 'sub' failed
> > fatal: The remote end hung up unexpectedly
> 
> I hope this clarifies my bug report.
> 
> Stefan, one little correction. I don't think the commit called out
> this behavior. The commit message was talking about unconfigured
> remotes (i.e. pushing to a url or local path) to not propagate the
> refspec and preserve the current behavior. Judging from the code and a
> test case that I wrote, this behavior is working as expected. That is,
> git won't propagate the refspec.
> 
> Cheers,
> 
> JS
> 
> On Mon, May 29, 2017 at 12:20 AM, Stefan Beller <sbeller@google.com> wrote:
> > On Sun, May 28, 2017 at 7:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
> >> John Shahid <jvshahid@gmail.com> writes:
> >>
> >>> It looks like the git push recurse-submodules behavior has changed.
> >>> Currently with 2.13 you cannot run "git push
> >>> --recurse-submodules=on-demand" if the parent repo is on a different
> >>> branch than the sub repos, e.g. parent repo is on "develop" and
> >>> sub-repo on "master". I created a test that can be found here [1].
> >>>
> >>> A bisect shows that the change to propagate refspec [2] to the
> >>> submodules is the culprit. imho this is an undesired change in
> >>> behavior. I looked at the code but couldn't see an easy way to fix
> >>> this issue without breaking the feature mentioned above. The only
> >>> option I can think of is to control the refspec propagation behavior
> >>> using a flag, e.g. "--propagate-refspecs" or add another
> >>> recurse-submodules option, e.g. "--recurse-submodules=propagate"
> >>>
> >>> What do you all think ?
> >>>
> >>> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
> >>> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
> >>
> >> Brandon?  I cannot quite tell from the report what "has changed"
> >> refers to, what failures "you cannot run" gets, and if that is a
> >> desirable thing to do (i.e. if letting the user run it in such a
> >> configuration would somehow break things, actively erroring out may
> >> be a deliberate change) or not (i.e. an unintended regression).
> >>
> >
> > Before the refspec was passed down into the submodules,
> > we'd just invoke "git push" in the submodule assuming the user
> > setup a remote tracking branch and a push strategy such that
> > "git push" would do the right thing.
> > And because the submodule is configured independently, it
> > doesn't matter which branch you're on in the superproject.
> >
> > Looking at the test[1], you run "git push --recurse-submodules"
> > without any remote/branch that was called out in the commit
> > message[2] to not have changed. Is that understanding correct?
> >
> > Looking at the test cases of [2] we did not test for explicit
> > "still works with no args given", though one could have expected
> > we'd have a test for that already. :/
> >
> > Thanks,
> > Stefan

-- 
Brandon Williams

Re: git push recurse.submodules behavior changed in 2.13

[Jonathan Nieder]

Hi John,

John Shahid wrote:

> It looks like the git push recurse-submodules behavior has changed.
> Currently with 2.13 you cannot run "git push
> --recurse-submodules=on-demand" if the parent repo is on a different
> branch than the sub repos, e.g. parent repo is on "develop" and
> sub-repo on "master". I created a test that can be found here [1].
>
> A bisect shows that the change to propagate refspec [2] to the
> submodules is the culprit. imho this is an undesired change in
> behavior. I looked at the code but couldn't see an easy way to fix
> this issue without breaking the feature mentioned above. The only
> option I can think of is to control the refspec propagation behavior
> using a flag, e.g. "--propagate-refspecs" or add another
> recurse-submodules option, e.g. "--recurse-submodules=propagate"

Thanks for reporting.  The old behavior of "git push
--recurse-submodules" was a little loose (it would run "git push" in
the submodule and rely on defaults to determine the behavior) and when
propagating refspecs we considered taking the opportunity to tighten
that by propagating the default refspec when you run "git push
--recurse-submodules" without a refspec.

We didn't make that change.  If starting over, it might be a natural
thing to do, but we didn't want to break existing users.  So

  git push --recurse-submodules=on-demand

should continue to work as before.  *puzzled*

[...]
> We have a parent repo on a branch called "develop" and a submodule on
> a branch called "master". Prior to git version 2.13 if we had an
> unpushed commit in the submodule and ran "git push origin develop
> --recurse-submodules=on-demand" git would happily push the develop
> branch of the parent repo and the master branch of the submodule,
[...]
> pushing to ref refs/heads/develop:refs/heads/develop
> pushging to remote origin
> fatal: src refspec 'refs/heads/develop' must name a ref
> fatal: process for submodule 'sub' failed
> fatal: The remote end hung up unexpectedly

Aha, you are passing a refspec!

Can you say more about how this change affects you?  Would you be able
to push without a refspec, or do you e.g. have scripting that was
relying on the existing loose behavior?

To put this in more context: part of the ideal that
--recurse-submodules options are trying to achieve is to allow
thinking of a repository as a single unit, including submodules, most
of the time.  To this end, "git clone --recurse-submodules" clones a
repository including its submodules, "git checkout
--recurse-submodules" checks out submodules as part of a checkout
operation, avoiding a separate "git submodule update --init" operation,
"git fetch --recurse-submodules" fetches upstream changes for both the
parent repository and submodules, and so on.

Unfortunately "git checkout --recurse-submodules" was missing a piece,
impacting this workflow.  If I run

	git checkout --recurse-submodules -b develop

then today this creates a "develop" branch in the superproject but not
within submodules. This hurts the illusion of the project being a single
unit and makes the meaning of operations like

	git push --recurse-submodules develop:master

unclear.

Ideas for next steps:

 1. If "git checkout --recurse-submodules -b develop" does the right
    thing, then this situation is harder to get in in the first place.
    The series at [3] is meant to do that.

 2. The error message shown above is very unclear. It leaks
    implementation details and doesn't give the user a clear hint
    about what to do to resolve it.  Would some message like the
    following have helped?

	$ git push --recurse-submodules origin develop
	fatal: branch "develop" does not exist in submodule "sub"
	hint: use "git -C sub branch develop <sha1>" to create such a branch
	hint: or push without a branch name to push the current branch

 3. Outside of the output from any particular command, we are missing
    an equivalent of "man gitworkflows" to describe how the
    --recurse-submodules options are meant to work.  The series at [4]
    aims to start addressing that.

Given all the above, this looks like a real and serious bug but I
think to find a different way from --recurse-submodules=propagate to
fix it.  The idea, especially with [5], is for submodules to work
intuitively without requiring special options.  This can require more
work in the short term getting the default behavior to work well with
a variety of use cases but I think it is time well spent.

Thoughts?

Thanks and hope that helps,
Jonathan

> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
[3] http://public-inbox.org/git/20170501180058.8063-1-sbeller@google.com/
[4] http://public-inbox.org/git/20170209020855.23486-1-sbeller@google.com/
[5] http://public-inbox.org/git/20170526191017.19155-1-sbeller@google.com/

Re: git push recurse.submodules behavior changed in 2.13

[John Shahid]

Hi Jonathan. Thanks a lot for the detailed and interesting response. I
included my comments/replies inline. tl;dr;

1. I love the idea of having tools treat the repo as a unit.
2. I think propagating the refspec when no refspec is passed on the
CLI is very surprising action that should be corrected
3. I propose more changes to the git tools to support the unity view of the repo

On Tue, May 30, 2017 at 2:10 PM, Jonathan Nieder <jrnieder@gmail.com> wrote:
> Hi John,
>
> John Shahid wrote:
>
>> It looks like the git push recurse-submodules behavior has changed.
>> Currently with 2.13 you cannot run "git push
>> --recurse-submodules=on-demand" if the parent repo is on a different
>> branch than the sub repos, e.g. parent repo is on "develop" and
>> sub-repo on "master". I created a test that can be found here [1].
>>
>> A bisect shows that the change to propagate refspec [2] to the
>> submodules is the culprit. imho this is an undesired change in
>> behavior. I looked at the code but couldn't see an easy way to fix
>> this issue without breaking the feature mentioned above. The only
>> option I can think of is to control the refspec propagation behavior
>> using a flag, e.g. "--propagate-refspecs" or add another
>> recurse-submodules option, e.g. "--recurse-submodules=propagate"
>
> Thanks for reporting. The old behavior of "git push
> --recurse-submodules" was a little loose (it would run "git push" in
> the submodule and rely on defaults to determine the behavior) and when
> propagating refspecs we considered taking the opportunity to tighten
> that by propagating the default refspec when you run "git push
> --recurse-submodules" without a refspec.
>
> We didn't make that change. If starting over, it might be a natural
> thing to do, but we didn't want to break existing users. So
>
> git push --recurse-submodules=on-demand
>
> should continue to work as before. *puzzled*
>
> [...]
>> We have a parent repo on a branch called "develop" and a submodule on
>> a branch called "master". Prior to git version 2.13 if we had an
>> unpushed commit in the submodule and ran "git push origin develop
>> --recurse-submodules=on-demand" git would happily push the develop
>> branch of the parent repo and the master branch of the submodule,
> [...]
>> pushing to ref refs/heads/develop:refs/heads/develop
>> pushging to remote origin
>> fatal: src refspec 'refs/heads/develop' must name a ref
>> fatal: process for submodule 'sub' failed
>> fatal: The remote end hung up unexpectedly
>
> Aha, you are passing a refspec!

Yes, we are used to passing a refspec but we will be happy not to if
that preserves the old behavior. In fact, the test case I linked to
earlier does not pass a refspec. I wrote the test that way because I
initially misunderstood the commit message and thought that not
passing a refspec preserves the old behavior. Long story short, I'm
happy with whatever option we have to maintain our current workflow.

>
> Can you say more about how this change affects you? Would you be able
> to push without a refspec, or do you e.g. have scripting that was
> relying on the existing loose behavior?

as i said before, pushing without a refspec would work for us. I'm
also talking to the team to see if we can switch the branch names to
be consistent, i.e. use either "master" or "develop" both in the
parent repo and sub repos.

>
> To put this in more context: part of the ideal that
> --recurse-submodules options are trying to achieve is to allow
> thinking of a repository as a single unit, including submodules, most
> of the time. To this end, "git clone --recurse-submodules" clones a
> repository including its submodules, "git checkout
> --recurse-submodules" checks out submodules as part of a checkout
> operation, avoiding a separate "git submodule update --init" operation,
> "git fetch --recurse-submodules" fetches upstream changes for both the
> parent repository and submodules, and so on.
>
> Unfortunately "git checkout --recurse-submodules" was missing a piece,
> impacting this workflow. If I run
>
> git checkout --recurse-submodules -b develop
>
> then today this creates a "develop" branch in the superproject but not
> within submodules. This hurts the illusion of the project being a single
> unit and makes the meaning of operations like
>
> git push --recurse-submodules develop:master
>
> unclear.
>
> Ideas for next steps:
>
> 1. If "git checkout --recurse-submodules -b develop" does the right
> thing, then this situation is harder to get in in the first place.
> The series at [3] is meant to do that.
>
> 2. The error message shown above is very unclear. It leaks
> implementation details and doesn't give the user a clear hint
> about what to do to resolve it. Would some message like the
> following have helped?
>
> $ git push --recurse-submodules origin develop
> fatal: branch "develop" does not exist in submodule "sub"
> hint: use "git -C sub branch develop <sha1>" to create such a branch
> hint: or push without a branch name to push the current branch
>
> 3. Outside of the output from any particular command, we are missing
> an equivalent of "man gitworkflows" to describe how the
> --recurse-submodules options are meant to work. The series at [4]
> aims to start addressing that.

I would also add to that list, "git pull --rebase
-recurse-submodules", "git merge --recurse-submodules", etc. Otherwise
"git checkout --recurse-submodules develop" won't make much sense,
since you'll have to go to each submodules and make sure the local
branch is up to date.

I like the idea of treating the entire repo as a single unit. In fact
the new feature (to propagate refspec) is very useful to me. For
example, when working on feature branches across the entire repo. That
said, i think "git push --recurse-submodules=on-demand" should do the
least surprising action and push the current branch, where "current"
is defined wrt the repo being pushed (and "push.default" of course).
Taking the refspec from the parent repo and forcing it on the
submodules feels weird to me.

>
> Given all the above, this looks like a real and serious bug but I
> think to find a different way from --recurse-submodules=propagate to
> fix it. The idea, especially with [5], is for submodules to work
> intuitively without requiring special options. This can require more
> work in the short term getting the default behavior to work well with
> a variety of use cases but I think it is time well spent.

>
> Thoughts?
>
> Thanks and hope that helps,
> Jonathan

Yes, that definitely helped. This track of work makes more sense now.
Thanks again for the detailed response.

JS

>
>> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
>> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
> [3] http://public-inbox.org/git/20170501180058.8063-1-sbeller@google.com/
> [4] http://public-inbox.org/git/20170209020855.23486-1-sbeller@google.com/
> [5] http://public-inbox.org/git/20170526191017.19155-1-sbeller@google.com/

Re: git push recurse.submodules behavior changed in 2.13

[John Shahid]

bump. it's been a while and I'm still not clear what the next steps
are. I'm happy to send a patch but I would like to get a consensus
first.

On Wed, May 31, 2017 at 10:50 AM, John Shahid <jvshahid@gmail.com> wrote:
> Hi Jonathan. Thanks a lot for the detailed and interesting response. I
> included my comments/replies inline. tl;dr;
>
> 1. I love the idea of having tools treat the repo as a unit.
> 2. I think propagating the refspec when no refspec is passed on the
> CLI is very surprising action that should be corrected
> 3. I propose more changes to the git tools to support the unity view of the repo
>
> On Tue, May 30, 2017 at 2:10 PM, Jonathan Nieder <jrnieder@gmail.com> wrote:
>> Hi John,
>>
>> John Shahid wrote:
>>
>>> It looks like the git push recurse-submodules behavior has changed.
>>> Currently with 2.13 you cannot run "git push
>>> --recurse-submodules=on-demand" if the parent repo is on a different
>>> branch than the sub repos, e.g. parent repo is on "develop" and
>>> sub-repo on "master". I created a test that can be found here [1].
>>>
>>> A bisect shows that the change to propagate refspec [2] to the
>>> submodules is the culprit. imho this is an undesired change in
>>> behavior. I looked at the code but couldn't see an easy way to fix
>>> this issue without breaking the feature mentioned above. The only
>>> option I can think of is to control the refspec propagation behavior
>>> using a flag, e.g. "--propagate-refspecs" or add another
>>> recurse-submodules option, e.g. "--recurse-submodules=propagate"
>>
>> Thanks for reporting. The old behavior of "git push
>> --recurse-submodules" was a little loose (it would run "git push" in
>> the submodule and rely on defaults to determine the behavior) and when
>> propagating refspecs we considered taking the opportunity to tighten
>> that by propagating the default refspec when you run "git push
>> --recurse-submodules" without a refspec.
>>
>> We didn't make that change. If starting over, it might be a natural
>> thing to do, but we didn't want to break existing users. So
>>
>> git push --recurse-submodules=on-demand
>>
>> should continue to work as before. *puzzled*
>>
>> [...]
>>> We have a parent repo on a branch called "develop" and a submodule on
>>> a branch called "master". Prior to git version 2.13 if we had an
>>> unpushed commit in the submodule and ran "git push origin develop
>>> --recurse-submodules=on-demand" git would happily push the develop
>>> branch of the parent repo and the master branch of the submodule,
>> [...]
>>> pushing to ref refs/heads/develop:refs/heads/develop
>>> pushging to remote origin
>>> fatal: src refspec 'refs/heads/develop' must name a ref
>>> fatal: process for submodule 'sub' failed
>>> fatal: The remote end hung up unexpectedly
>>
>> Aha, you are passing a refspec!
>
> Yes, we are used to passing a refspec but we will be happy not to if
> that preserves the old behavior. In fact, the test case I linked to
> earlier does not pass a refspec. I wrote the test that way because I
> initially misunderstood the commit message and thought that not
> passing a refspec preserves the old behavior. Long story short, I'm
> happy with whatever option we have to maintain our current workflow.
>
>>
>> Can you say more about how this change affects you? Would you be able
>> to push without a refspec, or do you e.g. have scripting that was
>> relying on the existing loose behavior?
>
> as i said before, pushing without a refspec would work for us. I'm
> also talking to the team to see if we can switch the branch names to
> be consistent, i.e. use either "master" or "develop" both in the
> parent repo and sub repos.
>
>>
>> To put this in more context: part of the ideal that
>> --recurse-submodules options are trying to achieve is to allow
>> thinking of a repository as a single unit, including submodules, most
>> of the time. To this end, "git clone --recurse-submodules" clones a
>> repository including its submodules, "git checkout
>> --recurse-submodules" checks out submodules as part of a checkout
>> operation, avoiding a separate "git submodule update --init" operation,
>> "git fetch --recurse-submodules" fetches upstream changes for both the
>> parent repository and submodules, and so on.
>>
>> Unfortunately "git checkout --recurse-submodules" was missing a piece,
>> impacting this workflow. If I run
>>
>> git checkout --recurse-submodules -b develop
>>
>> then today this creates a "develop" branch in the superproject but not
>> within submodules. This hurts the illusion of the project being a single
>> unit and makes the meaning of operations like
>>
>> git push --recurse-submodules develop:master
>>
>> unclear.
>>
>> Ideas for next steps:
>>
>> 1. If "git checkout --recurse-submodules -b develop" does the right
>> thing, then this situation is harder to get in in the first place.
>> The series at [3] is meant to do that.
>>
>> 2. The error message shown above is very unclear. It leaks
>> implementation details and doesn't give the user a clear hint
>> about what to do to resolve it. Would some message like the
>> following have helped?
>>
>> $ git push --recurse-submodules origin develop
>> fatal: branch "develop" does not exist in submodule "sub"
>> hint: use "git -C sub branch develop <sha1>" to create such a branch
>> hint: or push without a branch name to push the current branch
>>
>> 3. Outside of the output from any particular command, we are missing
>> an equivalent of "man gitworkflows" to describe how the
>> --recurse-submodules options are meant to work. The series at [4]
>> aims to start addressing that.
>
> I would also add to that list, "git pull --rebase
> -recurse-submodules", "git merge --recurse-submodules", etc. Otherwise
> "git checkout --recurse-submodules develop" won't make much sense,
> since you'll have to go to each submodules and make sure the local
> branch is up to date.
>
> I like the idea of treating the entire repo as a single unit. In fact
> the new feature (to propagate refspec) is very useful to me. For
> example, when working on feature branches across the entire repo. That
> said, i think "git push --recurse-submodules=on-demand" should do the
> least surprising action and push the current branch, where "current"
> is defined wrt the repo being pushed (and "push.default" of course).
> Taking the refspec from the parent repo and forcing it on the
> submodules feels weird to me.
>
>>
>> Given all the above, this looks like a real and serious bug but I
>> think to find a different way from --recurse-submodules=propagate to
>> fix it. The idea, especially with [5], is for submodules to work
>> intuitively without requiring special options. This can require more
>> work in the short term getting the default behavior to work well with
>> a variety of use cases but I think it is time well spent.
>
>>
>> Thoughts?
>>
>> Thanks and hope that helps,
>> Jonathan
>
> Yes, that definitely helped. This track of work makes more sense now.
> Thanks again for the detailed response.
>
> JS
>
>>
>>> [1] https://gist.github.com/jvshahid/b778702cc3d825c6887d2707e866a9c8
>>> [2] https://github.com/git/git/commit/06bf4ad1db92c32af38e16d9b7f928edbd647780
>> [3] http://public-inbox.org/git/20170501180058.8063-1-sbeller@google.com/
>> [4] http://public-inbox.org/git/20170209020855.23486-1-sbeller@google.com/
>> [5] http://public-inbox.org/git/20170526191017.19155-1-sbeller@google.com/

Re: git push recurse.submodules behavior changed in 2.13

[Stefan Beller]

On Sat, Jun 10, 2017 at 6:28 AM, John Shahid <jvshahid@gmail.com> wrote:
> bump. it's been a while and I'm still not clear what the next steps
> are. I'm happy to send a patch but I would like to get a consensus
> first.

What do you want a consensus on?
(Is the change in 2.13 a bug or feature? I considered it enough
of a feature to not pursue an urgent bug fix. Maybe I misunderstood
the discussion)

This thread has diverged into lots of things that could be done. Jonathan
pointed out 3 possible ways forward. (1) and (3) are being worked on,
(2) is a new thing that nobody (not Brandon nor me) have on our radar
for what to work on next.  So maybe that is a good idea to get started
when you want to get into sending a patch?

Also I have the impression that there may be one corner case, in which
the handling of refspecs is missed, i.e. maybe we'd need a list (in the
man page eventually) on what currently happens when recursing in
combination with remote/refspecs or other options.

Re: git push recurse.submodules behavior changed in 2.13

[John Shahid]

On Mon, Jun 12, 2017 at 1:27 PM, Stefan Beller <sbeller@google.com> wrote:
> On Sat, Jun 10, 2017 at 6:28 AM, John Shahid <jvshahid@gmail.com> wrote:
>> bump. it's been a while and I'm still not clear what the next steps
>> are. I'm happy to send a patch but I would like to get a consensus
>> first.
>
> What do you want a consensus on?
> (Is the change in 2.13 a bug or feature? I considered it enough
> of a feature to not pursue an urgent bug fix. Maybe I misunderstood
> the discussion)

I was under the impression that Jonathan and may be others considered
the fact that `git push --recurse-submodules=on-demand` doesn't work
as before an unintentional change. He asked me previously if pushing
without a refspec will work for us and I responded with a yes. The
question remains if everyone is on board with change push without
refspec to use `push.default` in the parent repo as well as
submodules.

Cheers,

JS