Take care of stack traces too!

[chenglou]

Fatal error: exception Not_found
Raised at file "src/reason_toolchain.ml", line 87, characters 10-13
Called from file "src/reason_toolchain.ml", line 233, characters 14-57
Called from file "src/refmt_impl.ml", line 12, characters 48-157
Called from file "src/refmt_impl.ml", line 153, characters 18-69
File "src/Nuclide.re", line 1:
Error: Error while running external preprocessor
Command line: refmt 'src/Nuclide.re' > /var/folders/r0/dg6dl1qn2l91cq_2k1lg11v501nwsp/T/ocamlppc2cbe7

This could be formatted better. For example, formatting those files to be clickable from the command line, like we do currently for compiler errors. Plus: display better messages when there's no stack trace (e.g. "please enable -g etc.)

[wbeard]

@chenglou What do you think about creating a more machine-readable format alongside this? This is something I wish was baked into JavaScript, and could be a great feature.

[chenglou]

Hello! Are you on discord? discord.gg/reasonml We can talk there as this might be long