$ git clone -n https://src.fedoraproject.org/rpms/rust-portable-atomic.git /var/lib/mock/f45-build-43925-809/root/chroot_tmpdir/scmroot/rust-portable-atomic
Cloning into '/var/lib/mock/f45-build-43925-809/root/chroot_tmpdir/scmroot/rust-portable-atomic'...
$ git fetch origin 286402041f6cd8851fbd05205c7bbd566b42be29:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-portable-atomic
 * [new ref]         286402041f6cd8851fbd05205c7bbd566b42be29 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2864020 Update to version 1.15.0; Fixes RHBZ#2512955