$ git clone -n https://src.fedoraproject.org/rpms/rust-platforms.git /var/lib/mock/f39-build-1547319-36717/root/chroot_tmpdir/scmroot/rust-platforms
Cloning into '/var/lib/mock/f39-build-1547319-36717/root/chroot_tmpdir/scmroot/rust-platforms'...
$ git fetch origin 55f4eafce8ec4015a26bc649bcba7f5dd6fee271:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-platforms
 * [new ref]         55f4eafce8ec4015a26bc649bcba7f5dd6fee271 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 55f4eaf Package unretirement and update to version 3.1.2 (#2242764)