vcs export exits with error if there are local branches that don't track remote branches

[tvu-outrider]

If I create a local branch and run vcs export; it exits with error. See the sequence of actions taken to reproduce this issue below:

git switch -c tmp/fails
Switched to a new branch 'tmp/fails'

vcs export
repositories:
Could not determine ref: fatal: no upstream configured for branch 'tmp/fails'

Proposed solution: modify

vcstool/vcstool/clients/git.py

Line 213 in daf3893

'returncode': 1,

so the return code is 0

My use case is to gather git version information to be embedded in an executable; but this issue causes an error in the build script.
I don't think not having an upstream remote warrants an error here; and it would play more nicely with my build script if the exit code is not an error. I understand that this is an annoyance specific to my use case, just want to see if there's a chance the solution can be adopted upstream.