[cmake] Add explicit RIO dependency in MathCore

[silverweed]

As an attempt to fix the build issues ("RIO.pcm is out of date") seen e.g. here on debian (due to dev=on)

[ferdymercury]

Thanks. One question: isn't the failure happening in the generate-dictionary of tree/ntuple (G__ROOTNTuple.cxx) rather than in MathCore?

Related solution: #18858
and issues:
#7704
#8518

[silverweed]

Thanks. One question: isn't the failure happening in the generate-dictionary of tree/ntuple (G__ROOTNTuple.cxx) rather than in MathCore?

Related solution: #18858 and issues: #7704 #8518

Not sure, but considering RNTuple already lists RIO in its dependencies I thought MathCore was more likely to be the culprit (if the two dictionaries are built in parallel it would make sense - then again, no idea if they are)

[guitargeek]

Thanks! I don't mind trying this out

[hageboeck]

I'm not convinced yet that this is the solution. See this:

echo "  ROOT/RRawFile.hxx
  ROOT/RRawFileTFile.hxx
  ${rawfile_local_headers}
  ROOT/TBufferMerger.hxx
  TArchiveFile.h
  TBufferFile.h
  TBufferText.h
  TBufferIO.h
  TBufferJSON.h
  TCollectionProxyFactory.h
  TContainerConverters.h
  TEmulatedMapProxy.h
  TEmulatedCollectionProxy.h
  TDirectoryFile.h
  TFileCacheRead.h
  TFileMerger.h
  TFree.h
  TFileCacheWrite.h
  TFilePrefetch.h
  TFile.h
  TFPBlock.h
  TGenCollectionStreamer.h
  TGenCollectionProxy.h
  TKey.h
  TKeyMapFile.h
  TLockFile.h
  TMemFile.h
  TMapFile.h
  TMakeProject.h
  TStreamerInfoActions.h
  TVirtualCollectionIterators.h
  TStreamerInfo.h
  TZIPFile.h" | while read file; do git grep $file math/mathcore/; done

This is all headers listed in RIO's CMake, and checking if they are used anywhere in mathcore. The only hit is math/mathcore/test/stress, but this one explicitly lists that dependency. We would therefore introduce a spurious dependency.
I'm not sure that this is really causing the pcm problems, so introducing an unneeded dependency would go against all efforts of reducing those dependencies that we tried to do in the past.

[github-actions]

Test Results

    22 files      22 suites   3d 21h 42m 45s ⏱️
 3 692 tests  3 687 ✅ 0 💤 5 ❌
79 276 runs  79 271 ✅ 0 💤 5 ❌

For more details on these failures, see this check.

Results for commit 2e6e453.

[silverweed]

Thank you @hageboeck, I mistakenly thought RIO had a dependency on TFile but then you made me realize it's specifically avoided via an eval-style trick.
I guess we need to dig deeper.
Closing this.