$ git clone -n https://src.fedoraproject.org/rpms/rust-tree_magic_mini.git /var/lib/mock/f45-build-45739-825/root/chroot_tmpdir/scmroot/rust-tree_magic_mini
Cloning into '/var/lib/mock/f45-build-45739-825/root/chroot_tmpdir/scmroot/rust-tree_magic_mini'...
$ git fetch origin 75fdc54ce1159e17a1116774d2f97822c8ad249d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tree_magic_mini
 * [new ref]         75fdc54ce1159e17a1116774d2f97822c8ad249d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75fdc54 Remove unused, benchmark-only dev-dependency on bencher