FMUs depend on libgfortran.so.3

[jluttine]

I'm following the introductory tutorial under doc. I'm getting the following error:

File "introductory.py", line 131, in __main__
Failed example:
    weather = exodata.WeatherFromEPW('USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw')
Exception raised:
    Traceback (most recent call last):
      File "/nix/store/l95nkqp7bdimqnz9ixay1aahljzsz7vc-python-2.7.15/lib/python2.7/doctest.py", line 1315, in __run
        compileflags, 1) in test.globs
      File "<doctest __main__[19]>", line 1, in <module>
        weather = exodata.WeatherFromEPW('USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw')
      File "/home/jluttine/Workspace/MPCPy/mpcpy/exodata.py", line 794, in __init__
        self._create_fmu({'fmupath': weatherdir+os.sep+fmuname});
      File "/home/jluttine/Workspace/MPCPy/mpcpy/utility.py", line 423, in _create_fmu
        self.fmu = load_fmu(self.fmupath);
      File "src/pyfmi/fmi.pyx", line 7943, in pyfmi.fmi.load_fmu
      File "src/pyfmi/fmi.pyx", line 7086, in pyfmi.fmi.FMUModelME2.__init__
      File "src/pyfmi/fmi.pyx", line 3824, in pyfmi.fmi.FMUModelBase2.__init__
    FMUException: Error loading the binary. Could not load the DLL: libgfortran.so.3: cannot open shared object file: No such file or directory

It is trying to read this FMU: resources/weather/WeatherProcessor_JModelica_v2.fmu

Apparently, the FMU depends on an older gfortran file than I have on my system. I "fixed" this by installing an older gfortran. But I don't understand how FMUs can be portable if they have such very system-dependent dependencies? Shouldn't the FMU either include the library file it needs or be more flexible what it can use? Or are FMUs just very tied to the environment and you aren't supposed to use them in very different environments? I'm new to FMUs so I don't really know. I'm just wondering because these FMUs are part of the repo so I was expecting that they'd work. If they aren't expected to work when copied to a different environment, perhaps provide a way to generate/compile these FMUs?

[jluttine]

Another workaround: I opened the FMU file as a zip file, added libgfortran.so.3 there, and it started working. Perhaps the FMU in the repo could include the library file already?

[jluttine]

I can make a pull request once I get this all figured out if you want.

[dhblum]

Thanks for reporting this issue. Please, so I can understand the issue better, can you tell me the OS and version you are using?