$ git clone -n https://src.fedoraproject.org/rpms/rust-hmac.git /var/lib/mock/f45-build-42364-793/root/chroot_tmpdir/scmroot/rust-hmac
Cloning into '/var/lib/mock/f45-build-42364-793/root/chroot_tmpdir/scmroot/rust-hmac'...
$ git fetch origin 2fbe59b07a7192737c1f7c2f091e7f023c0e2d8d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-hmac
 * [new ref]         2fbe59b07a7192737c1f7c2f091e7f023c0e2d8d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2fbe59b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild