$ git clone -n https://src.fedoraproject.org/rpms/rust-bytesize.git /var/lib/mock/f42-build-59123337-6571232/root/chroot_tmpdir/scmroot/rust-bytesize
Cloning into '/var/lib/mock/f42-build-59123337-6571232/root/chroot_tmpdir/scmroot/rust-bytesize'...
$ git fetch origin f39e363107c835977c4ecc1ed63796baf73d1bfe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bytesize
 * [new ref]         f39e363107c835977c4ecc1ed63796baf73d1bfe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f39e363 Update to version 1.3.3