$ git clone -n https://src.fedoraproject.org/rpms/rust-bumpalo.git /var/lib/mock/f38-build-side-42-init-devel-1395353-31050/root/chroot_tmpdir/scmroot/rust-bumpalo
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1395353-31050/root/chroot_tmpdir/scmroot/rust-bumpalo'...
$ git fetch origin e35c3e6fe29840823636910227ccab568ea224b4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bumpalo
 * [new ref]         e35c3e6fe29840823636910227ccab568ea224b4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e35c3e6 Update to version 3.14.0; Fixes RHBZ#2239025