Re: git pull bug report

From: Bryan Turner <bturner@atlassian.com>
Date: Nov 15, 2021, 17:56 UTC
Message-ID: <CAGyf7-H5icSmOQ1eDx9RXDTwFcB2y9sgUxNNTF7V7Xu1MfHTEA@mail.gmail.com>
In-Reply-To: <CADL96rvRX2R_4Wm23tz88hDUztcpK531RU+Ops2UVoiOW0bCHw@mail.gmail.com>

On Mon, Nov 15, 2021 at 12:42 AM Erwin Villejo <erwinvillejo@gmail.com> wrote:

Show 41 quoted lines

>
> > What did you do before the bug happened? (Steps to reproduce your issue)
> * make local changes, stage, and commit
> * local is ahead of upstream. confirmed by `git status`:
>
> ```
> $ git status
> On branch main
> Your branch is ahead of 'github/main' by 1 commit.
>   (use "git push" to publish your local commits)
> ```
>
> * try to pull upstream to local
>
> > What did you expect to happen? (Expected behavior)
> No-op (and NO failure) since local is ahead of upstream.
>
> > What happened instead? (Actual behavior)
> `git pull` fails with error:
>
> ```
> $ git pull
> hint: You have divergent branches and need to specify how to reconcile them.
> hint: You can do so by running one of the following commands sometime before
> hint: your next pull:
> hint:
> hint:   git config pull.rebase false  # merge (the default strategy)
> hint:   git config pull.rebase true   # rebase
> hint:   git config pull.ff only       # fast-forward only
> hint:
> hint: You can replace "git config" with "git config --global" to set a default
> hint: preference for all repositories. You can also pass --rebase, --no-rebase,
> hint: or --ff-only on the command line to override the configured default per
> hint: invocation.
> fatal: Need to specify how to reconcile divergent branches.
> ```
>
> > What's different between what you expected and what actually happened?
> I expected no failure and no-op since local is ahead of upstream.
> Instead, `git pull`
> fails because it thinks the branches have diverged.

You're making a logical, but still incorrect, assumption about what the "git status" output means. "git status" does NOT actually check the remote server.

When you pull, there are typically 3 refs that are involved, not 2. (Given it appears you're on "main", I'll use that name below.) refs/heads/main: This is the local branch you're working on refs/remotes/github/main: This is your _local copy_ of what the _remote_ branch was pointed at the last time you fetched or pulled successfully refs/heads/main on Github: This is the remote branch you're trying to push to

When you run "git status", it is NOT talking to Github; it's simply comparing the state of your "refs/heads/main" and "refs/remotes/github/main" branches.

When you run "git pull", it's actually talking to Github, which allows it to find out about commits that are present remotely but have not been fetched to your "refs/heads/main" or "refs/remotes/github/main" branches.

If you run "git fetch", rather than "git pull", that will update your local "refs/remotes/github/main" branch without trying to also update "refs/heads/main". If you then run "git status", it will tell you your "main" branch has diverged, just like "git pull" does, instead of showing it as ahead.

Hope this helps, Bryan

Show 27 quoted lines

>
> > Anything else you want to add:
> I found this bug in VSCode. VSCode runs `git pull` first before `git
> push` when pushing to upstream.
> This bug causes pushing via VSCode to always fail, although it can be
> worked around by simply opening
> a terminal and running `git push` manually.
>
> [System Info]
> git version:
> git version 2.33.1
> cpu: x86_64
> no commit associated with this build
> sizeof-long: 8
> sizeof-size_t: 8
> shell-path: /bin/sh
> uname: Linux 5.15.2-arch1-1 #1 SMP PREEMPT Fri, 12 Nov 2021 19:22:10
> +0000 x86_64
> compiler info: gnuc: 11.1
> libc info: glibc: 2.33
> $SHELL (typically, interactive shell): /bin/bash
>
>
> [Enabled Hooks]
>
> Best regards,
> Erwin