Dear Maintainer,
When using rubber -Wrefs (or rubber -Wall) on a latex document containing
some undefined reference (e.g. \ref{foo} without any corresponding
\label{foo}),
rubber does not report any warning about these undefined references as it
should.
I'm using Debian bookworm, hence rubber 1.6.0-2, but the testing/sid version
of rubber seem to suffer from the same issue.
Issue already reported upstream: https://gitlab.com/latex-
rubber/rubber/-/issues/15
The provided 2-line patch appears to solve this issue.
Best regards
Pierre L.