$ git clone -n https://src.fedoraproject.org/rpms/binutils.git /var/lib/mock/f42-build-861803-170352/root/chroot_tmpdir/scmroot/binutils
Cloning into '/var/lib/mock/f42-build-861803-170352/root/chroot_tmpdir/scmroot/binutils'...
$ git fetch origin 00b3ac3d67ca43e3cf4604e3e47c17fcaa18cdba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/binutils
 * [new ref]         00b3ac3d67ca43e3cf4604e3e47c17fcaa18cdba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 00b3ac3  Rebase to commit 1686dc7079f