lix run <lib> issues

[Antriel]

• https://github.com/lix-pm/haxeshim/blob/master/src/haxeshim/HaxelibCli.hx#L60 uses haxelib.json's mainClass, but it should be just main based on docs.
• It doesn't consider the default value of "main": "Run".
• It doesn't actually implement running the interpreter.

The first 2 should be easy enough, not sure about actually running it. Would it come down to just callHaxelib(['run', name].concat(args)) or would it be better to call haxe directly?

[kevinresol]

I think we should invoke the compiler directly instead of going through haxelib?

[kevinresol]

We need to do the followings to mimic the behaviour of haxelib:

1. cwd of the running process would be the location of the haxelib
2. append an extra call arg, which is the location of the "caller" (cwd where haxelib run is called)
3. set env var "HAXELIB_RUN" to "1"
4. set env var "HAXELIB_RUN_NAME" to <lib_name>

[kevinresol]

main class support is added in 9c75d35

I think we still need to support the default value of "main": "Run".

[back2dos]

Corresponding haxelib code: https://github.com/HaxeFoundation/haxelib/blob/443307307eb2ed1aeb576fa2c8c2afc0f896d18e/src/haxelib/client/Main.hx#L1687