Jenkins Multibranch project trowes fatal: ambiguous argument 'upstream/master': unknown revision or path not in the working tree. for the PR build

Question

I am working on a project same as this question. Even though I used the same solution still i'am getting below error. Is anything updated in git recently? or anyone have solution to fix it?

16:48:06  + git rev-parse upstream/master
16:48:06  fatal: ambiguous argument 'upstream/master': unknown revision or path not in the working tree.
16:48:06  Use '--' to separate paths from revisions, like this:
16:48:06  'git <command> [<revision>...] -- [<file>...]'
16:48:06  upstream/master

Poul

It is telling you that the branch upstream/master does not exist on the server. – Piecework

Answer 1

I found the solution finally. adding ref specs to project fixed the issue.

Poul

This helped me greatly. – Waylin