[GHC] #16015: git notes logic breaks CircleCI validation of pull requests

[GHC]

#16015: git notes logic breaks CircleCI validation of pull requests
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.6.3
       Component:  Compiler          |              Version:  8.6.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by davide):

 P.S. I've looked at CI runs since ​https://circleci.com/gh/ghc/ghc/12493
 and confirmed that PRs all fail to push git notes due to missing
 credentials. Non-PR triggered CI runs either push the notes successfully,
 or skip pushing due to
 [https://github.com/ghc/ghc/commit/0f2ac24c26fb951cc81100085c7773906a241523
 #diff-91a1cfa1c62d468507f51bd4ea7e7fcd this change].

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16015#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler