$ git clone -n https://src.fedoraproject.org/rpms/ghc-dotgen.git /var/lib/mock/f38-build-side-42-init-devel-861464-28428/root/chroot_tmpdir/scmroot/ghc-dotgen
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-861464-28428/root/chroot_tmpdir/scmroot/ghc-dotgen'...
$ git fetch origin bfbb1e2a7c72249170284bcc78766d39558d1ffc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-dotgen
 * [new ref]         bfbb1e2a7c72249170284bcc78766d39558d1ffc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bfbb1e2 Convert to %autorelease and %autochangelog