Handling of failing addon entry_points

[bollwyvl]

References

• from Allow Addons to provide CLI aliases and flags #934

Problem

from #934 (comment)

       try:
           addon_implementations[name] = entry_point.load()
       except Exception as err:  # pragma: no cover
           warnings.warn(f"[lite] [{name}] failed to load: {err}")

It could be convenient if this was an exception instead, I've seen cases where the xeus-python addon would fail to load and it would have been convenient for jupyter lite build to not continue building.

Proposed Solution

Some options:

• check the strict mode (True by default) and fail on any entry_point.load()
  • maybe still try to .load() all of them, and collect and print all the errors together
    • getting all of the tracebacks is often useful, though, too
  • this is a breaking change, but not a huge one

• ??? please add more :P

Additional context

...

[martinRenou]

Thanks for opening an issue tracking this!

this is a breaking change, but not a huge one

Is it?

[bollwyvl]

Replied at some point, but apparently it got lost.

I think anything that causes a hard fail where before there wasn't one is kinda breaking. But perhaps this is more of a bug, if the default of --strict=True was meant to fail fast. Either way, we should take a look at what e.g. nbconvert does, which also uses entry_points for extensibility.