Add support for 'hidden=True' easyconfig parameter

[geimer]

This complements the '--hidden' command-line option.

[boegel]

@geimer: build_option('hidden') is also used in process_easyconfig, do we need to check the hidden parameter there too?

Looks tricky at first sight, since it's used before parsing the easyconfig, and I'm not sure it's strictly needed there...

[geimer]

@boegel: Something like hidden = hidden or ec['hidden'] in the if not parse_only: block may do the trick. What do you think?

[geimer]

Of course I meant easyconfig['hidden'] instead of ec['hidden'] ;-)

[geimer]

@boegel: I believe the easyconfig update for hidden in L1230 isn't necessary. The build_option is passed to the EasyConfig constructor, which will correctly initialize the value based on build_option and the hidden easyconfig parameter. Does that make sense?

[geimer]

@boegel: Still trying to understand the code...

Shouldn't the update in https://github.com/geimer/easybuild-framework/blob/5d9a56a543eb7f8e078d6aa737077cfc23be40ed/easybuild/framework/easyconfig/easyconfig.py#L1230 be 'hidden': ec.hidden? Then the first query to build_option('hidden') only affects the cache lookup, which should be OK as the data in the cache should already include parsed values. The update then takes the actual parsed value into account, determined in the EasyConfig constructor based on the build option and the easyconfig parameter.

The thing is that the easyconfig unit tests all pass, regardless of what the update does. I can even hard-code it to True or False...

BTW: There is a docstring for the parse_only parameter missing.

[boegel]

@geimer I think you're right with your last comment. Up until now it didn't really matter, but with the introduction of the hidden easyconfig parameter, it does matter.

I'd have to dive in and figure out where that 'hidden' key is actually used, if at all, it may be "dead code", but it certainly doesn't hurt to get it right (and using ec.hidden is correct imho).

The cache aspect is a bit weird, but only taking into account --hidden in the cache key is correct imho, since the hidden easyconfig parameter only comes into play when the easyconfig is already parsed.

[geimer]

@boegel: IMHO, this is ready for review.

[boegel]

@geimer looks good, but I couldn't resist making a few minor tweaks, see geimer#8

[boegel]

Going in, thanks @geimer!