Generated Erlang fails to compile

[David00154]

I'm on an ubuntu18 machine with erlang and gleam properly installed. Any time i run gleam run in my project folder i get an error

vagrant@ubuntu-18:/home/gleam/gleam_project$ gleam run
Compiling gleam_stdlib
Compiling gleeunit
Compiling gleam_project
build/dev/erlang/gleam_project/gleam@@main.erl:13: illegal pattern
build/dev/erlang/gleam_project/gleam@@main.erl:14: variable 'Reason' is unbound
build/dev/erlang/gleam_project/gleam@@main.erl:14: variable 'StackTrace' is unbound
error: Shell command failure

There was a problem when running the shell command erlc.

[michallepicki]

Hi @David00154 !

This looks like a situation where Gleam compilation "succeeded" but resulting Erlang code is invalid or can't be compiled by your Erlang version.

What's your Gleam compiler version? With current Gleam my resulting .erl file is in a slightly different directory at build/dev/erlang/gleam_project/build/gleam@@main.erl (there's one more build)

What's your Erlang version (what did you use to install it on Ubuntu 18.04)?

Does it succeed on a clean compile (after running gleam clean)? There still might be some bugs that require cleaning sometimes.

If it will still be an issue, can you provide your src/gleam_project.gleam file and what will be the resulting .erl file? Or better yet, since it sounds like it always happens for you, would you be able to provide a minimal reproduction example? Or maybe upload an archive with all files from your project?

[lpil]

Line 13 of that file is this

        Class:Reason:StackTrace ->
            print_error(Class, Reason, StackTrace),
            erlang:halt(127, [{flush, true}])

That makes me think this is an older version of Erlang that didn't have the stacktrace variable in try/catch yet. That would fit with it being the one packaged for Ubuntu 18.04.

Could you try a newer version of Erlang? I think that will fix the problem.

I'll convert this to a discussion as I think there is nothing for us to fix in the compiler here, but do let me know if I am wrong.