[CMake] MinGW-w64/MSYS2 (or Cygwin) and NAG Fortran - how to combine?

[Brad King]

On 2/9/2018 2:36 AM, Arjen Markus wrote:
> From: Alan W. Irwin
>> I suggest you try the names CYGWIN-NAG-Fortran.cmake and
>> Windows-NAG-Fortran.cmake for the two separate Platform
>> files you are trying to create for the Cygwin and
>> MinGW-w64/MSYS2 platforms.

I think those names are correct.  However, the status of CMake
for MSYS2-native builds is unclear.  See below.

> I have a Platform file “Windows-NAG-Fortran.cmake” and that is used
> correctly if I start the NAG Fortran environment (using the MinGW
> Makefiles generator)

Good.

> but if I try the same with MinGWw-w64/MSYS2, this file is clearly ignored

What is the value of CMAKE_SYSTEM_NAME that is detected?

Typically this should be "Windows" for a Windows-native CMake
and "CYGWIN" for a cygwin-built CMake that is linked against the
cygwin runtime library.

For MSYS2 what CMake are you running?  A Windows CMake or one
that came packaged by MSYS2?  Does the latter link against the
msys2 runtime library?

-Brad