Problem when running scenario.solve()

[DrUkachi]

Dear Community,
I am trying to use the message_ix library to work on predicting the energy mix. Currently I am trying out the Tutorial notebooks provided in the documentation and each time I run this line:

scenario.solve()

I get the following error

---------------------------------------------------------------------------
CalledProcessError                        Traceback (most recent call last)
<ipython-input-35-4fce57630f1c> in <module>
      1 #import message_ix
      2 
----> 3 scenario.solve()

~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\core.py in solve(self, model, solve_options, **kwargs)
    563             :class:`.GAMSModel`.
    564         """
--> 565         super().solve(model=model, solve_options=solve_options, **kwargs)
    566 
    567     def add_macro(self, data, scenario=None, check_convergence=True, **kwargs):

~\Anaconda3\envs\ws1-env\lib\site-packages\ixmp\core.py in solve(self, model, callback, cb_kwargs, **model_options)
   1672         # Iterate until convergence
   1673         while True:
-> 1674             model.run(self)
   1675 
   1676             # Store an iteration number to help the callback

~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\models.py in run(self, scenario)
    361 
    362         try:
--> 363             result = super().run(scenario)
    364         finally:
    365             # Remove the optfile regardless of whether the run completed

~\Anaconda3\envs\ws1-env\lib\site-packages\ixmp\model\gams.py in run(self, scenario)
    180         # Invoke GAMS
    181         cwd = self.temp_dir if self.use_temp_dir else model_file.parent
--> 182         check_call(command, shell=os.name == "nt", cwd=cwd)
    183 
    184         # Read model solution

~\Anaconda3\envs\ws1-env\lib\subprocess.py in check_call(*popenargs, **kwargs)
    362         if cmd is None:
    363             cmd = popenargs[0]
--> 364         raise CalledProcessError(retcode, cmd)
    365     return 0
    366 

CalledProcessError: Command 'gams "C:~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\model\MESSAGE_run.gms" --in="C:~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\model\data\MsgData_Westeros_Electrified_baseline.gdx" --out="C:~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\model\output\MsgOutput_Westeros_Electrified_baseline.gdx" --iter="C:~\Anaconda3\envs\ws1-env\lib\site-packages\message_ix\model\output\MsgIterationReport_Westeros_Electrified_baseline.gdx" LogOption=4' returned non-zero exit status 7.

I am using a Windows 10 OS machine. I would appreciate any feedbacks and suggestions on how to solve this issue.
Thank you.

[khaeru]

Per the GAMS documentation, an exit status of 7 (end of the last line of your message) indicates a licensing error.

Can you please say which version of GAMS you have installed? message-ix show-versions on the command line will display this information. If the version is ≥30, please re-read the installation instructions carefully per which version to install.

[DrUkachi]

Thank you for your reply @khaeru. Please find the results of running the message-ix show-versions command

ixmp:        3.2.0
message_ix:  3.2.0
message_data: None
'gams' is not recognized as an internal or external command,

click:       7.1.2
dask:        2021.03.0
graphviz:    0.16
jpype:       1.2.1
… JVM path:  ~\envs\ws1-env\Library\bin\server\jvm.dll
openpyxl:    3.0.7
pandas:      1.2.3
pint:        0.17
xarray:      0.17.0
yaml:        5.4.1

iam_units:   installed
jupyter:     installed
matplotlib:  3.3.4
plotnine:    0.8.0
pyam:        0.10.0

GAMS:        'gams' executable not in PATH

python:      3.8.8 | packaged by conda-forge | (default, Feb 20 2021, 15:50:08) [MSC v.1916 64 bit (AMD64)]
python-bits: 64
OS:          Windows
OS-release:  10
machine:     AMD64
processor:   Intel64 Family 6 Model 142 Stepping 10, GenuineIntel
byteorder:   little
LC_ALL:      None
LANG:        None
LOCALE:      English_Nigeria.1252

operable program or batch file.

Does this show that I have a higher version of message-ix and would a pip install message-ix ==29.0 help?

[khaeru]

Does this show that I have a higher version of message-ix and would a pip install message-ix ==29.0 help?

No, the first lines show that you already have message_ix: 3.2.0, the latest version. This should be fine.

These show that GAMS is not installed correctly:

'gams' is not recognized as an internal or external command, operable program or batch file.

GAMS:        'gams' executable not in PATH