$ git clone -n https://src.fedoraproject.org/rpms/R-stringr.git /var/lib/mock/f39-build-1544836-36669/root/chroot_tmpdir/scmroot/R-stringr
Cloning into '/var/lib/mock/f39-build-1544836-36669/root/chroot_tmpdir/scmroot/R-stringr'...
$ git fetch origin 15d207ce870df4cbedd3af47d0893c4130de4f2f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-stringr
 * [new ref]         15d207ce870df4cbedd3af47d0893c4130de4f2f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15d207c Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild