Inconsistencies between using setup and bare cmake

[robertodr]

I think configuring a project with setup and bare cmake should lead to the exact same result, but this is not currently the case:

1. setup sets compilers as FC=gfortran cmake. I think it is better to pass them as CMake variables: cmake -DCMAKE_Fortran_COMPILER=gfortran, which is also portable.
2. setup creates the build directory beforehand and then moves into it before running cmake. With bare cmake I do cmake -H. -Bbuild (also portable) I encountered this problem because I am running a configuration script that needs cmake to be run from the root directory (I know this is bad practice)
3. For some reason, running bare cmake leads the math detector to believe that I want to use MKL. I haven't investigated this last problem more.

Possible solutions:

1. If you agree, I can change this rather easily. Some of the code in configure.py and generate.py can be simplified/removed.
2. I would keep the check on existing build directories (though this is not CMake behavior and it might confuse people used to bare cmake) but generate the CMake command as cmake -H<project_root_dir> -B<build_path>.

[bast]

I agree with you that "configuring a project with setup and bare cmake should lead to the exact same result" and I can imagine that it may not always and when it does not, I consider it a bug or bad design of some of the components. This is important when a project is included as external project.

1. Agree. What you describe is clearly better. I simply did not know better in the past. Will also simplify Windows and as you say remove a lot of clutter.
2. Agree. It's more portable. But I really want to know what -H means and perhaps rather use the --long-flags for more clarity. This will be mostly transparent but if somebody goes into the code that they have an idea what is happening.
3. We can look at it but good to have a concrete example that I can copy paste into my terminal.

[robertodr]

I will send a PR for this. My example for the moment was hande-qmc/hande#2, but really, any project using Autocmake will be an example. For -H the documentation says it will output an help message if called without a directory as argument.

[bast]

So we can leave out the -H? Since the script will always call it with an argument.

[robertodr]

I feel -H is the proper way of doing it, even if it's undocumented.