haskell / haskell/haskell-mode
Invariant failed: a warning message from GHC has unexpected form
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- Dominant language
- Emacs Lisp
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Description
My haskell-mode 20160827.1033 complains about the following problem when I have an unused variable in my source code:
```
haskell-error-overlay-briefly: Invariant failed: a warning message from GHC has unexpected form: warning: [-Wunused-matches]
Defined but not used: ‘banned’.
```
I'm using GHC 8.0.1 on Linux/x86_64.
Contributor guide
Research direction
Start with haskell-error-overlay-briefly and reproduce the warning using GHC 8.0.1 on Linux/x86_64 with an unused variable such as “banned”. Inspect how the warning form is handled; done means this GHC warning no longer triggers an invariant failure and is displayed correctly.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- emacs, haskell
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100