roc-lang
stack overflow / bus error if there's an alias reference to a mutually recursive type
If you have this file:
platform "roc-lang/rbt"
requires {} { init : Job }
exposes []
packages {}
imports []
provides [initForHost]
initForHost : Job
initForHost = init
Input : [FromProjectSource, FromJob Job]
Job : [Job { inputs : List Input }]
job : { inputs : List Input } -> Job
job = \config -> Job config
On running roc check, you'll get a stack overflow or a bus error (depending on build type.)
If you remove the Job member of the FromJob tag, or the type annotation for job, the error goes away. I guess FromProjectSource is not strictly required either (the error still happens without it) but I did all my testing with that in place so into the bug report it goes!
This is true as of da75f55aeacc18b452d3e359557599e1c1eca006, but I tested back to 3a12aa26ccb347a2374c01e960d37f77b8b3b8b0 and the bug is present.
@ayazhafiz I feel like you might know right away what this could be—does it seem familiar?
further messing around:
- if you simplify to
job : Input -> Job, you'll still get the stack overflow - if you simplify to
job : Job -> Job, you won't
I have a good idea of what it is, but how to resolve it has eluded us for a while. I think this may be the same as https://github.com/roc-lang/roc/issues/3216. I'll take a closer look tomorrow!
