$ git clone -n https://src.fedoraproject.org/rpms/rust-os_str_bytes.git /var/lib/mock/f39-build-1494111-34542/root/chroot_tmpdir/scmroot/rust-os_str_bytes
Cloning into '/var/lib/mock/f39-build-1494111-34542/root/chroot_tmpdir/scmroot/rust-os_str_bytes'...
$ git fetch origin 7d30526dc62f5f619e70b4e25ac255997b0fd822:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-os_str_bytes
 * [new ref]         7d30526dc62f5f619e70b4e25ac255997b0fd822 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7d30526 Update to version 6.6.1; Fixes RHBZ#2244216