$ git clone -n https://src.fedoraproject.org/rpms/ghc-attoparsec.git /var/lib/mock/f39-build-1713645-41228/root/chroot_tmpdir/scmroot/ghc-attoparsec
Cloning into '/var/lib/mock/f39-build-1713645-41228/root/chroot_tmpdir/scmroot/ghc-attoparsec'...
$ git fetch origin b6467b4b7eaec3ff03550f4f48e8310c4d9bd7fd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-attoparsec
 * [new ref]         b6467b4b7eaec3ff03550f4f48e8310c4d9bd7fd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b6467b4 revised .cabal file