ASSERT failed compiler/typecheck/TcMType.lhs line 809
With current master (9c2dade9) I get
[1 of 1] Compiling ShouldCompile ( ../ghc/gadt6.hs, ../ghc/gadt6.o )
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 7.7.20131121 for x86_64-unknown-linux):
ASSERT failed!
file compiler/typecheck/TcMType.lhs line 809
[W] cobox_aBx{v} [lid] :: t_aBv{tv} [tau[0]]
ghc-prim:GHC.Types.~{(w) tc 31Q} t_aBu{tv} [tau[0]] (CIrredEvCan)(And it took me a while to figure out that it was not my code that was introducing the bug.)
According to git log -L 809,809:compiler/typecheck/TcMType.lhs (a useful feature) the history of the ASSERT is:
- SPJ, “Accommodate Derived constraints in two places”, Sep 17, 8cfbdccb
- SPJ, “Fix an ASSERT”, Oct 1 2012, adb6bcb7
- SPJ, “Tidy up and simplify TcMType.zonkFlats”, Sep 17, 2012, bd6b183e
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.6.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (Type checker) |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |