Change datadir

[langston-barrett]

Is there a way to change the datadir? I'm building Herms with Nix, and the datadir is a path in the Nix store:

/nix/store/n8ql2a3x0j0ciq05lnsn3pvlm5m8f7sa-herms-1.9.0.1-data/share/ghc-8.2.2/x86_64-linux-ghc-8.2.2/herms-1.9.0.1/

which is read-only. Can I change this setting with a command line flag or environment variable?

If not, consider this a feature request, one that I'd be willing to implement (pointers appreciated!).

[langston-barrett]

It seems like getDataDir is some cabal magic set at compile-time and that it is used before options are parsed, so it will take a bit of fiddling to be able to set it using a command-line option. An environment variable might be a good stopgap.

[LuxMiranda]

This is a great idea! I played around with this a bit when first implementing datadir, (I think it'd be great to just have a ~/.herms directory), but I also realized that there's some shadowy arcane machinations behind the scenes that make it a little more difficult than anticipated. I'll add it to the requested feature list!

[langston-barrett]

@JackKiefer Thanks. I plan to implement an environment variable soon.

[langston-barrett]

Another way forward (with other benefits) would be XDG compliance. We already import directory, which provides getXdgDirectory. This would obviate ad-hoc environment variable parsing overriding defaults, etc. since the user can just change their XDG_* variables.

[langston-barrett]

Closed in #65