$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rspec-mocks.git /var/lib/mock/f45-build-35230-694/root/chroot_tmpdir/scmroot/rubygem-rspec-mocks
Cloning into '/var/lib/mock/f45-build-35230-694/root/chroot_tmpdir/scmroot/rubygem-rspec-mocks'...
$ git fetch origin cbe178e9d7cbbf9dd2ae0237dbba9b626b8e11a9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rspec-mocks
 * [new ref]         cbe178e9d7cbbf9dd2ae0237dbba9b626b8e11a9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cbe178e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild