When there is a new commit in a new branch, no notification is sent and error message is this one (and we expect MQTT notifications on each new push/commit)

Writing objects: 100% (3/3), 303 bytes | 303.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0)
remote: ERROR: [u'git', u'rev-list', u'e6bd15828f6841ccf51fb3c5955052751f8cd487', u'^HEAD'] =-- 128
remote: 
remote: fatal: bad revision '^HEAD'
remote: 
remote: Sending to redis to send commit notification emails

Then, on the second commit/push in the same branch, notifications are working fine and json payload pushed to correct topic on mqtt broker

This is one example (but easy to reproduce) :
https://git.dev.centos.org/rpms/glibc/tree/c7-sig-core

Worth knowing that in our pagure instance[s], as we normally had to merge with Fedora, we have no master branch, and RCM is pushing only to c7/c8 branches, even when creating a new project through pagure api.

So wondering if that's also tied to https://pagure.io/pagure/issue/4571 about "unborn" HEAD ?