$ git clone -n https://src.fedoraproject.org/rpms/ghc-IOSpec.git /var/lib/mock/f40-build-2048024-48982/root/chroot_tmpdir/scmroot/ghc-IOSpec
Cloning into '/var/lib/mock/f40-build-2048024-48982/root/chroot_tmpdir/scmroot/ghc-IOSpec'...
$ git fetch origin dd2b1d5e3bd8294d4156795b161db4db9207bd03:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-IOSpec
 * [new ref]         dd2b1d5e3bd8294d4156795b161db4db9207bd03 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dd2b1d5 bump release