GHC shows core with error

The following code intentionally does not compile:

{-# LANGUAGE DataKinds, KindSignatures, PolyKinds #-}

data Proxy (p :: k) = Proxy
data Tagged (t :: k) s = Tagged s

proxy :: Tagged t s -> Proxy t -> s
proxy = undefined

bar :: Tagged (gad :: *) Int
bar = undefined

foo :: Int
foo = proxy bar (Proxy::Proxy 'True)

but it produces the following output with GHC and GHCi:

[1 of 1] Compiling Main             ( Bug.hs, interpreted )
RAE1
  [W] cobox_aLM :: t0_aK4[tau:1] ~ 'True (CNonCanonical)
  t0_aK4[tau:1]
  'True
  False

Bug.hs:13:18:
    Couldn't match kind ‘Bool’ with ‘*’
    Expected type: Proxy t0
      Actual type: Proxy 'True
    In the second argument of ‘proxy’, namely ‘(Proxy :: Proxy True)’
    In the expression: proxy bar (Proxy :: Proxy True)
    In an equation for ‘foo’: foo = proxy bar (Proxy :: Proxy True)
Failed, modules loaded: none.

This ticket is about the first block printed out. It seems to be a random section of core, and is completely useless to debugging the problem.

Trac metadata

Trac field	Value
Version	7.10.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed weight to 5

added Tbug Trac import labels

Well, that's embarrassing -- it's a bit of debug output I put in at some point. (My initials are RAE. I use them in all my debugging output I intend to remove, for easy searching.)

I can't reproduce this on 7.10.2. What version of GHC are you working with? A quick search shows that this problem isn't in the current codebase.

That output was with version 7.10.2.20151030.

closed

As far as I can tell, this output is no longer produced on the ghc-7.10 branch (or in HEAD), so I'm going to close this ticket. Sorry for leaking this output into an RC!

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

added error messages label

added Pnormal label