Build History for pull/402

Gracefully handle deleted packages in analysis Previously, the analysis phase didn't expect any package deletions. So, we'd fail with the error "impossible". But, with the new opam-repository archival process, we allow for deletions, even though only in the special case of a package being archived.

Gracefully handle deleted packages in analysis Previously, the analysis phase didn't expect any package deletions. So, we'd fail with the error "impossible". But, with the new opam-repository archival process, we allow for deletions, even though only in the special case of a package being archived.

Skip deleted packages in analysis