ParseConfig does not populate paths for Fortran

[kprussing]

After running env.ParseConfig, the environment variable "CPPPATH" is populated, but the Fortran equivalents "F90PATH" and friends are not. A nice to have would be for env.ParseConfig to populate these Fotran variables so libraries that install Fortran stubs in /usr/include like FFTW3 could be found auto-magically.

Required information

• Link to SCons Users thread discussing your issue: Discord thread
• Version of SCons: 4.10.1
• Version of Python: 3.14.3
• Which python distribution if applicable: conda-forge
• How you installed SCons: pip install scons
• What Platform are you on? RHEL8 (tested on, original author of thread mentioned macOS)
• How to reproduce your issue? See below

Additional context

SConstruct

env = Environment()

env.ParseConfig("pkg-config fftw3 --cflags --libs")

# If FFTW3 was installed in /usr/include, we need additional flags
if env.get("CPPPATH") is None:
    env.ParseConfig("pkg-config fftw3 --cflags --libs --keep-system-cflags")

print("CPPPATH: ", env["CPPPATH"])
for key in ["F77PATH",
            "F90PATH",
            "F95PATH",
            "F03PATH",
            "F08PATH",
            ]:
    # Force copy of CPPPATH to the appropriate Fortran dialect path
    env[key] = env["CPPPATH"]

env.Program("mwe.f90")

mwe.f90

program mwe
    use iso_c_binding
    include 'fftw3.f03'
end program mwe