$ git clone -n https://src.fedoraproject.org/rpms/ghc-base16-bytestring.git /var/lib/mock/f41-build-835771-158635/root/chroot_tmpdir/scmroot/ghc-base16-bytestring
Cloning into '/var/lib/mock/f41-build-835771-158635/root/chroot_tmpdir/scmroot/ghc-base16-bytestring'...
$ git fetch origin b8f85f96f2a3f66b69bb0a5b246da4eb2a85e7ef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-base16-bytestring
 * [new ref]         b8f85f96f2a3f66b69bb0a5b246da4eb2a85e7ef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b8f85f9 revise .cabal file