bug: `util.scandir` borked on OS X

[p3r7]

hey!

the issue

so util.scandir relies on ls to list files in a directory. but it uses the --group-directories-first option (src) to have directories listed before regular files in the output,. but this flag is only available for the GNU version of ls (OS X comes w/ BSD's version).

paths of resolution

i see 3 ways to fix this:

• drop the --group-directories-first flag (meh as we'd loose feature parity w/ norns)
• have coreutils be a dependency to seamstress on OS X and call gls instead of ls
• use an alternative method, such as successive calls to find (per this rec)

2 & 3 both require to be able to test the current OS in the Lua layer. idk if seamstress exposes a global w/ that info already or if this is something that would need to be added.

also this fix would be back-ported to norns itself (for allowing to run norns-desktop on OS X, which is something that got discussed recently).

[robbielyman]

i don't really have a strong opinion here – i've never used util.scandir on norns or seamstress. i would like not to make seamstress depend on coreutils, although i suppose it's not onerous.

seamstress could definitely expose the current os itself, but calling uname is right there already...