#8066: Compiler Panic When Using Instance Derivation With Singletons
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Reporter: tvynr | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.6.3
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
Type of failure: Compile-time crash | Unknown/Multiple
Test Case: | Difficulty: Unknown
Blocking: | Blocked By:
| Related Tickets:
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Comment (by simonpj):
The HEAD gives
{{{
T8066.hs:42:22:
No instance for (SingE QualForm (KindOf QualForm a))
arising from the 'deriving' clause of a data type declaration
Possible fix:
use a standalone 'deriving instance' declaration,
so you can specify the instance context yourself
When deriving the instance for (Show (TVar a))
}}}
Does that seem more reasonable? We've fixed lots of kind-related bugs in
7.6.
If the error looks ok, can we close the ticket?
Simon
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8066#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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