global -p option

[drwebb]

@snoyberg Any suggestions for naming these options: --local-bin-path seems to make sense, but I'm not a fan of -p. Also note that the invocation will be a lot more natural once #519 is implemented.

[snoyberg]

I'm -1 on the -p shorthand. I'd say --install-path would be better, but perhaps @manny-fp would have input. Frankly, even --path seemed OK, but now that it's a global option I can see making it a bit more explicit would be worthwhile.

[snoyberg]

This won't work if the directory doesn't already exist. Possible solution: call createDirectoryIfMissing True userPath first. Not sure if it's worth it.

[drwebb]

Summary of commit be8dbb1:

Dropped -p short option. I like --path as well but --local-bin-path is a little more explicit that we are just copying the binaries to that location. I'm still up to changing to --install-path though might imply other things than just the bin. As it it --local-bin-path is clear at the expense of looking a little unconventional.

I am opposed to employing createDirectoryIfMissing. We want the user to see something like

λ church stack → λ git userlocalbin* → ~/.local/bin/stack --local-bin-path ./binz install
Could not locate user specified directory "./binz"
IOException: ./binz: canonicalizePath: does not exist (No such file or directory)

Basically fail fast and hard on a typo, not silently doing what the user doesn't want.

The other change was to match only on IOException, which is the only thing that I think canonicalizePath can throw. Looking at the code for Path, it can throw a PathParseException which I will go ahead and cover.

[drwebb]

Summary of 55a5476:
Also catching PathParseExceptions right there, never been able to trigger it (canonicalizePath seems to catch any nastyness) though.

[drwebb]

@snoyberg: I talked with @manny-fp about the naming and he also liked --local-bin-path as one can already use stack path --local-bin-path. I should also make sure the new field in the stack.yaml will follow the same convention, so if this looks good to you I'll handle the merge.

[snoyberg]

@manny-fp Please merge when you're ready, I'm fine with this PR.

[borsboom]

Should not be using error, instead throw a new ConfigException constructor.