Deriving Data does not work for attached code
I get the following error when I try to derive Data for the attached code:
Main.hs:17:66:
Couldn't match expected type `Bar (D a b)'
with actual type `t' a1 b1'
Expected type: Maybe (c (Bar (D a b)))
Actual type: Maybe (c (t' a1 b1))
In the expression: gcast2 f
In an equation for `dataCast2': dataCast2 f = gcast2 fTrac metadata
| Trac field | Value |
|---|---|
| Version | 7.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | mmitar@gmail.com |
| Operating system | |
| Architecture |