$ git clone -n https://src.fedoraproject.org/rpms/ghc-ConfigFile.git /var/lib/mock/f41-build-side-1-2811396-32930/root/chroot_tmpdir/scmroot/ghc-ConfigFile
Cloning into '/var/lib/mock/f41-build-side-1-2811396-32930/root/chroot_tmpdir/scmroot/ghc-ConfigFile'...
$ git fetch origin 34d63e456bed12efcd89813aa41451d983a67599:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-ConfigFile
 * [new ref]         34d63e456bed12efcd89813aa41451d983a67599 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 34d63e4 FTBFS and last release 10 years ago