Any way to update only repos that are on a branch ?

[MaxandreOgeret]

Hello, I have multiple repos in my .repos file and some are on a branch and some other are on tags.

To update my repos I would like to pull all the repos that are on branch automatically and

vcs custom --git --args pull will also try to pull repos that are on a tag or commit number and the pull will fail and my command will return a non-zero code, which is not convenient to put it in a script.
But the command did what I wanted though !

Here's the output of my command :

$ vcs custom --git --args pull

EEEE....
=== ./src/common (git) ===
Already up to date.
=== ./src/core_perception (git) ===
Already up to date.
=== ./src/core_planning (git) ===
Already up to date.
=== ./src/drivers (git) ===
Already up to date.
=== ./src/messages (git) ===
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>
=== ./src/simulation (git) ===
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>
=== ./src/utilities (git) ===
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>
=== ./src/visualization (git) ===
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>

Thanks !

[MaxandreOgeret]

duplicate #165