Can't checkout branch

Can't checkout branch

[Larry Martell]

Been using git for a long time, first time I have seen this. I am
unable to checkout a branch.

$ git status
# On branch master
nothing to commit, working directory clean

$ git fetch --all
Fetching origin
 * [new branch]      deploy     -> origin/deploy

$ git checkout deploy
$ git branch
* master

$ git checkout origin/deploy
Note: checking out 'origin/deploy'.

You are in 'detached HEAD' state.

I tried deleting the local repo and recloning, but I got the same
results. I see the branch on github. I can checkout other branches,
just not this one.

What could be going on?

Re: Can't checkout branch

[Chris Torek]

On Tue, Jul 14, 2020 at 10:04 AM Larry Martell <larry.martell@gmail.com> wrote:
[snippage]
> $ git fetch --all
> Fetching origin
>  * [new branch]      deploy     -> origin/deploy
>
> $ git checkout deploy
> $ git branch
> * master
>
> $ git checkout origin/deploy
> Note: checking out 'origin/deploy'.
>
> You are in 'detached HEAD' state.
>
> I tried deleting the local repo and recloning, but I got the same
> results. I see the branch on github. I can checkout other branches,
> just not this one.
>
> What could be going on?

This happens in Git versions prior to 2.23 (what Git version are
you using?) when there is a *file or directory* named `deploy`.

What is happening is that since there is no *branch* named
deploy (yet), you can't check it out (yet).  So `git checkout
deploy` initially fails.  The checkout command then goes on
to try two alternatives:

 1. Treat this as `git checkout -- deploy`, i.e.,
    extract the file or subtree named `deploy` from
    the index (discarding changes to that file or
    subtree).

 2. Treat this as `git checkout -b deploy origin/deploy`
    or `git checkout -t origin/deploy`, i.e., create the
    branch `deploy` from `origin/deploy`.

If *both* of these alternatives work, pre-2.23 Git *assumes* you
meant alternative number 1.  In 2.23 or later, `git checkout`
tells you that this is ambiguous and makes you pick which one you
want.

To work around this in all versions of Git, you can just be
more explicit.  For instance:

    git checkout deploy --

forces Git to treat it as a branch name.

Chris

Re: Can't checkout branch

[Junio C Hamano]

Chris Torek <chris.torek@gmail.com> writes:

>  2. Treat this as `git checkout -b deploy origin/deploy`
>     or `git checkout -t origin/deploy`, i.e., create the
>     branch `deploy` from `origin/deploy`.
>
> If *both* of these alternatives work, pre-2.23 Git *assumes* you
> meant alternative number 1.  In 2.23 or later, `git checkout`
> tells you that this is ambiguous and makes you pick which one you
> want.
>
> To work around this in all versions of Git, you can just be
> more explicit.  For instance:
>
>     git checkout deploy --
>
> forces Git to treat it as a branch name.

I actually think "git checkout -t -b deploy origin/deploy" is a
better way to be explicit to avoid confusion.  You do not create a
branch every few seconds anyway---it is more important to instill in
user's head what really does go on by encouraging them to give these
command line arguments explicitly, instead of teaching new people to
rely on "git guesses most of the time in your favor so here is the
lazy command line"---that will prevent true understanding and if it
left unremedied long enough, will result in a confused user who is
no longer a newbie.

Having said that, yes "git checkout deploy --" is a way to still
rely on git guessing most of the time in your favor to stay lazy,
and it should work, but there may be unseen other factors to break
the DWIM, just like Larry didn't think of an existing file deploy
in the working tree to be interfering.

Thanks.

Re: Can't checkout branch

[Larry Martell]

On Tue, Jul 14, 2020 at 2:18 PM Chris Torek <chris.torek@gmail.com> wrote:
>
> On Tue, Jul 14, 2020 at 10:04 AM Larry Martell <larry.martell@gmail.com> wrote:
> [snippage]
> > $ git fetch --all
> > Fetching origin
> >  * [new branch]      deploy     -> origin/deploy
> >
> > $ git checkout deploy
> > $ git branch
> > * master
> >
> > $ git checkout origin/deploy
> > Note: checking out 'origin/deploy'.
> >
> > You are in 'detached HEAD' state.
> >
> > I tried deleting the local repo and recloning, but I got the same
> > results. I see the branch on github. I can checkout other branches,
> > just not this one.
> >
> > What could be going on?
>
> This happens in Git versions prior to 2.23 (what Git version are
> you using?) when there is a *file or directory* named `deploy`.
>
> What is happening is that since there is no *branch* named
> deploy (yet), you can't check it out (yet).  So `git checkout
> deploy` initially fails.  The checkout command then goes on
> to try two alternatives:
>
>  1. Treat this as `git checkout -- deploy`, i.e.,
>     extract the file or subtree named `deploy` from
>     the index (discarding changes to that file or
>     subtree).
>
>  2. Treat this as `git checkout -b deploy origin/deploy`
>     or `git checkout -t origin/deploy`, i.e., create the
>     branch `deploy` from `origin/deploy`.
>
> If *both* of these alternatives work, pre-2.23 Git *assumes* you
> meant alternative number 1.  In 2.23 or later, `git checkout`
> tells you that this is ambiguous and makes you pick which one you
> want.
>
> To work around this in all versions of Git, you can just be
> more explicit.  For instance:
>
>     git checkout deploy --
>
> forces Git to treat it as a branch name.

Thanks for the reply - that was indeed the issue - I had a dir named deploy.

Re: Can't checkout branch

[Andreas Schwab]

On Jul 14 2020, Chris Torek wrote:

> To work around this in all versions of Git, you can just be
> more explicit.  For instance:
>
>     git checkout deploy --
>
> forces Git to treat it as a branch name.

For recent versions of git, you can also use `git switch deploy'.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: Can't checkout branch

[Junio C Hamano]

Andreas Schwab <schwab@linux-m68k.org> writes:

> On Jul 14 2020, Chris Torek wrote:
>
>> To work around this in all versions of Git, you can just be
>> more explicit.  For instance:
>>
>>     git checkout deploy --
>>
>> forces Git to treat it as a branch name.
>
> For recent versions of git, you can also use `git switch deploy'.

Yes, that is the best piece of advice in the thread so far.

Thanks.