It's possible that the external ELN repo for CentOS Stream 10 get's in a strange state so that source rpms cannot build.  When that happens we will get the external ELN repo fixed up, and it will get synced.  But, if that repo is not checked, then it is possible that CentOS Stream 10 builds will just fail until someone manually regenerates c10s-build.

Please set  'check_external_repos = true' for c10s-bootstrap