WorkDir CMake 3.15+ Fix, master branch (2020.02.02.)

This is a belated update along the same lines as how all the other projects in the repository have recently been updated in !29347 (merged).

Thanks to @christos for pointing this out. (That the WorkDir project no longer works against the latest nightly...) The necessary fixes were relatively minor in the end... Also, it's worth noting that the Fortran support in the WorkDir project has been broken for a loooong time. I guess nobody wanted to develop any Fortran code against a nightly in the last 1-2 years... (It should be fixed with this.)

This is relatively urgent, as people will start complaining tomorrow morning. Also, the CI is completely blind to these updates. So the RC will have to trust me on this...

Cc. @abarton, @wlampl, @emoyse, @fwinkl.

added master urgent labels

This merge request affects 1 package:

• Projects/WorkDir

Adding @rbianchi as watcher

added Build review-pending-level-1 labels

added RC Attention Required label

merged

mentioned in commit 40132a3f

I think I managed to merge it just in time so people have a working nightly on Monday morning...

Hey thanks. Btw just by merging this back to my branch

cmake -DATLAS_PACKAGE_FILTER_FILE=../package_filters.txt ../athena/Projects/WorkDir -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

seems to be fine

Btw, whether this is “in the nightly”, doesn’t make a difference. This updated code will have to be in the local clones of the developers.

So since I’m on vacation, you guys will have to tell people from tomorrow to rebase their feature branches if they have problems...

CI Result SUCCESS (hash dace9592)

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 9032]

added sweep:ignore label

resolved all threads

@akraszna you are hard-coding the WorkDir version here to 1.0.0, which is not good. E.g. in the trigger we rely on this being the Athena version. Otherwise the build behaves different between full release and WorkDir builds:

https://gitlab.cern.ch/atlas/athena/blob/master/Trigger/TriggerCommon/TriggerMenuMT/CMakeLists.txt#L45

I'll try to make a fix...

I was wondering about this... I believe it should be okay to call find_package(...) before the project(...) call. So this should be solvable. Though I wonder if we should make that package rely on something other than ${CMAKE_PROJECT_VERSION}. (Though I don't have a good proposal at this point... )

Doing the project(...) call after find_package( Athena ) doesn't seem to work. I get some very strange errors with that. But calling it twice (first without version and then with proper version) seems to do the trick. The documentation doesn't say this is supported but the source code explicitly does: https://gitlab.kitware.com/cmake/cmake/blob/master/Source/cmProjectCommand.cxx#L61-66

So maybe we can go with that solution at least for the moment...

mentioned in merge request !30035 (merged)

It is definitely okay to call project(...) multiple times inside of a software project.

https://cmake.org/cmake/help/latest/variable/CMAKE_PROJECT_VERSION.html

But yeah, the description about project(...) is definitely not too obvious about this.

So okay, this could be good enough for now. But I'll definitely think a bit on how we could do it better. It just seems a bit too much of a hack. (Though for the WorkDir project, being a bit hacky, is not the end of the world...)

mentioned in commit 372de00e