$ git clone -n https://src.fedoraproject.org/rpms/dietlibc.git /var/lib/mock/f41-build-1457760-23578/root/chroot_tmpdir/scmroot/dietlibc
Cloning into '/var/lib/mock/f41-build-1457760-23578/root/chroot_tmpdir/scmroot/dietlibc'...
$ git fetch origin 054a3b9eb7336186e6f3e537bfd065ca7120fd55:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dietlibc
 * [new ref]         054a3b9eb7336186e6f3e537bfd065ca7120fd55 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 054a3b9 Fix improperly commented out macros in %prep