Setting up a proper modelling environment in Cygwin

[Marco Atzeri]

On 11.09.2020 04:37, Lawrence Bernardo via Cygwin wrote:
> Dear Cygwin users and developers,
> 
> I am trying to run some models based on the ROMS ocean modeling system. And
> although I mainly run such models on Linux supercomputing systems, I
> sometimes use Cygwin to make test runs. However, whenever I install Cygwin
> on a new PC, I often find that my set up on an older PC I had been using
> doesn't work properly. After looking deeper into the issues, it seems that
> proper compilation requires that the same fortran compiler (gfortran in
> this case) be used to compile the necessary components.
> 
> And as far as I understand, these components would mainly be:
> - zlib
> - hdf5
> - netcdf
> - netcdf-fortran
> - openmpi
> 
> As the gfortran compiler version number used for these different components
> is not indicated whenever I run cygwin setup-x86_64.exe, I am left to guess
> which version numbers for each to select. Of course, another option would
> be to accept the defaults for some components, and then compile my own
> version of say, netcdf, but this attempt almost always fails, and I'm not
> sure if this is due to conflicts with the already existing cygwin setup.
> 
> Given the issues above, would anyone have any suggestions or
> recommendations on how to best achieve the setup I would like to have? I
> will greatly appreciate any help.
> 
> Best regards,
> Lawrence
> --


for what I am aware the problem is only present with
fortran modules if you are using them.
C interface are not involved

zlib should not be involved as it has no fortran specific modules
same for hdf5.

Now the current gfortran has

$ zcat 
/usr/lib/gcc/x86_64-pc-cygwin/9.3.0/finclude/ieee_arithmetic.mod|head -n 1
GFORTRAN module version '15' created from ieee_arithmetic.F90

openmpi was built with last gcc so it is aligned

$ zcat /usr/lib/mpi.mod |head -n 1
GFORTRAN module version '15' created from mpi-ignore-tkr.F90

netcdf-fortran needs a rebuild

$ zcat /usr/include/netcdf.mod | head -n 1
GFORTRAN module version '14' created from netcdf4.f90

Give me some days for an update of the package
And I will need to re-build for test gcc 10 also,
but it is less urgent


Regards
Marco