Improving shell completions: hide certain commands

[fingolfin]

First off, thanks to @BoostCookie for adding shell completions in PR #753. (By the way I think this means #151 can be closed now?)

One very minor nitpick: if I enter juliaup then press TAB twice, I get this:

~$ juliaup
-h                                    status
-V                                    gc
--help                                config
--version                             api
default                               46029ef5-0b73-4a71-bff3-d0d05de42aac
add                                   0cf1528f-0b15-46b1-9ac9-e5bf5ccccbcf
link                                  info
list                                  self
override                              completions
update                                4c79c12db1d34bbbab1f6c6f838f423f
remove                                help

Note the weird UUIds / hex codes -- I think these are internal "commands", an implementation details -- I wonder if there is a way to hide them from the user?

I also think that -h, -V, --help, --version should be hidden -- that's also how shell completion for git and cargo is done (which both support --help and --version)

[davidanthoff]

Oh, yes, these uuid commands are internal and should definitely not be exposed to end-users in any way! They are just meant to be used from the julialauncher. I think that is something we should try to fix before we release a new build.

[BoostCookie]

When adding the completions I also noticed these uuid commands.
clap currently has an open issue about hiding some commands from the completions.

[davidanthoff]

Uh, that is a bit frustrating... Not entirely sure what we should do there, we definitely don't want end-users to start to run these internal commands, but I also see the value of these completions...