$ git clone -n https://src.fedoraproject.org/rpms/rubygem-activejob.git /var/lib/mock/f40-build-2033475-47808/root/chroot_tmpdir/scmroot/rubygem-activejob
Cloning into '/var/lib/mock/f40-build-2033475-47808/root/chroot_tmpdir/scmroot/rubygem-activejob'...
$ git fetch origin 3defdb46e658067052ef6a309e4ed52157dbe9a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-activejob
 * [new ref]         3defdb46e658067052ef6a309e4ed52157dbe9a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3defdb4 Update to activejob 7.0.8