Retrieve current CRAN check results to flag a different revdepcheck result

[cderv]

Related to #331

Currently, I don't think revdepcheck will in any case retrieve current CRAN check results for a reverse dependency check.

This would be an interesting information to detect some errors in the revdepcheck process as currently only old vs new differences are reported. However, it is possible like in #331 that old results are not similar to current CRAN check results and could lead to missed issues.

[gaborcsardi]

The CRAN machines have a different setup, so I am not sure if it worth comparing them to our results. We would see a lot of false positives, I am afraid.

[cderv]

What I would like to detect is

• The is no check issue on CRAN...
• but we check issue on our side for the CRAN revdep check

This means that the new vs old comparison is not good as 'old' is not a correct base.

This would allow to flag some results to look in more details.

[gaborcsardi]

but we check issue on our side for the CRAN revdep check

If you detect an issue during revdepcheck, then you investigate, I assume, so you would go to the cran page of the package, for which the report has a link afair, so you'll see there that there is no issue on CRAN. No? Or am I missing something?

There is no correct base, systems are different, cran has false positive check results, and so do we.

[cderv]

We could include the CRAN status of the revdeps in the report, so you can look at the ones that are failing on CRAN, maybe?

I think what you said in #331 can help flag what to look for.

If you detect an issue during revdepcheck, then you investigate, I assume, so you would go to the cran page of the package, for which the report has a link afair, so you'll see there that there is no issue on CRAN. No? Or am I missing something?

I'll share more on the feedback from our last knitr revdep check in the other issue. Maybe I am missing some results and did not look into the right place.

With knitr we have more than 7000 reverses dependencies checked, and which can be a lot to handle and investigate.