Streamlit and Pyomo: ValueError: signal only works in main thread

[jadoul...@googlemail.com]

Hello,

I was very curious to create a small Streamlit app using Pyomo.

Unfortunately, this leads to the following error:

______________________________________________________________________________

ValueError: signal only works in main thread

Traceback:

....

File "...\site-packages\pyomo\opt\base\solvers.py", 

line 582, in solve    _status = self._apply_solver()

File "...\site-packages\pyomo\opt\solver\shellcmd.py", 

line 244, in _apply_solver    self._rc, self._log = self._execute_command(self._command)

File "...\site-packages\pyomo\opt\solver\shellcmd.py", 

line 332, in _execute_command    self.process_soln_file(results)

File "...\site-packages\pyutilib\subprocess\processmngr.py", 

line 554, in run_command    #            = signal.signal(signal.SIGINT, handler)

File "...\lib\signal.py", 

line 47, in signal    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))

______________________________________________________________________________

By removing a few lines in processmngr.py, I could make it work.

These are the lines 548-556 dealing with  "define_signal_handlers" .

This works on my laptop.

Of course, this is not a good solution once I want to publish my Streamlit app  on  share.streamlit.io .

Would you have some suggestion to solve the problem without cutting lines of code in processmngr.py ?

I had a look to see if I could make use of process of threads, but this is beyond my competences and I guess there is not such solution. But who knows?

Any suggestion welcome!

Thanks

Michel