Broken plugin python file does not report error

[velocirobbie]

If my plugin file 'FabMD.py' has a syntax error or similar, typing

fab localhost lamms

returns:

`Warning: Command(s) not found:
lammps

Available commands:

archer                             partial(func, *args, **keywords) - new fun...
archive  ......`

It would be better if it said there was an error.

I assume somewhere fabric is catching this exception

[djgroen]

In general there are a few issues with the way Fabric captures exceptions in tasks. In addition, the list of commands shown is also not quite consistent with the structure of the plugins. We should investigate this in detail, ideally before M12.

[djgroen]

Okay, I found a solution for this, but it's a little tricky:

Basically, we need to override main.py in Fabric, and then modify the way that Fabric outputs diagnostics.

I now made a change on this, and I'll file a pull request for it.

[djgroen]

After discussion with @dww100 I think it makes sense to rename this overridden version from fab to fabsim. It will be functionally the same as fab, but the way it conveys info will hopefully be better.

I'm not sure yet if this should be in the M12 release, but we did have a lot of complaints about aspects surrounding this... any opinions?

[djgroen]

This issue is now solved. Question is whether we want to update our tutorials to use fabsim instead of the fab command...