JesterXL (Dec 01 2022 at 15:14): JesterXL (Dec 01 2022 at 15:14):Hey, I've managed to get roc repl + compiler to work on my Mac 12.6 Monterey, but roc test gets mad:
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: Erroneous', crates/compiler/mono/src/ir.rs:10148:10
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
I tried with/without the app header. I'm following the Roc tutorial docs.
Ayaz Hafiz (Dec 01 2022 at 15:15):What does roc check say? Do you have any type errors?
JesterXL (Dec 01 2022 at 15:15):── MISSING DEFINITION ─────────────────────────────────────────────── main.roc ─
main is listed as exposed, but it isn't defined in this module.
You can fix this by adding a definition for main, or by removing it
from exposes.
── TYPE MISMATCH ──────────────────────────────────────────────────── main.roc ─
This 2nd argument to isEq has an unexpected type:
20│ if count == 1 then
^
The argument is a number of type:
Num *
But isEq needs its 2nd argument to be:
Num * | * has Eq
────────────────────────────────────────────────────────────────────────────────
2 errors and 1 warning found in 14 ms.
Yeah, currently we have some bugs if you try to compile a Roc program that has type errors. That type error is a bug; I'm working on fixing it now. In the meantime you can use a type annotation as a workaround (https://roc.zulipchat.com/#narrow/stream/231634-beginners/topic/Type.20mismatch.20in.20if-then-else.20tutorial.20example/near/313227546)
Ayaz Hafiz (Dec 01 2022 at 15:21):Currently roc test does not exit early if there are type errors, which is why you saw the panic above, rather than a type error. We intend to change that soon.
JesterXL (Dec 01 2022 at 15:27):No worries, ok. I tried: pluralize : Str, Str, Num * -> Str and pluralize : Str, Str, Num -> Str, but both seem... off. Do you know what that 3rd param should be?
Ayaz Hafiz (Dec 01 2022 at 15:34):try pluralize : Str, Str, Num a -> Str | a has Eq
JesterXL (Dec 01 2022 at 15:42):Fascinating, same response:
── TYPE MISMATCH ──────────────────────────────────────────────────── main.roc ─
This 2nd argument to isEq has an unexpected type:
51│ if count == 1 then
^
The argument is a number of type:
Num *
But isEq needs its 2nd argument to be:
Num a | a has Eq
What if you say
one : Num a | a has Eq
one = 1
if count == one then ...
lol, here's what roc check says:
── TYPE MISMATCH ──────────────────────────────────────────────────── main.roc ─
Something is off with the body of the one definition:
51│ one : Num a | a has Eq
52│ one = 1
^
The body is a number of type:
Num *
But the type annotation on one says it should be:
Num a | a has Eq
Oh man, I'm sorry. I have a fix here: https://github.com/roc-lang/roc/pull/4644 - if it lands today it'll be in tomorrow's nightly release.
JesterXL (Dec 01 2022 at 16:17):Nooooo worries, it was fun to learn about the types!
JesterXL (Dec 01 2022 at 16:17):Appreciate your help and patience here.
Ayaz Hafiz (Dec 01 2022 at 22:59):The fix for this should be in the nightly release available tomorrow
Anton (Dec 02 2022 at 10:51):New nightly releases are published :)
Last updated: Jul 26 2025 at 12:14 UTC