Problem with interface file (.hi) for a particular function

I'm getting the following error:

Can't find interface-file declaration for mkNSElement

Probable cause: bug in .hi-boot file, or inconsistent .hi file

Use -ddump-if-trace to get an idea of which file caused the error

When trying to call the following function:

import Text.XML.HXT.Arrow


mkNSElement :: Num a => QName -> IOStateArrow [(String, a)] b XmlTree
            -> IOStateArrow [(String, a)] b XmlTree
mkNSElement qn cs = proc x -> do
                      nss <- getUserState -< x
                      let ns = namespaceUri qn
                          (pfx, s) = case lookup ns nss of
                                       Nothing -> (i+1, (ns, i+1):nss)
                                           where i = maximum (map snd nss)
                                       Just x  -> (x, nss)
                          pfx' = "q" ++ show pfx
                          qn' = qn { namePrefix=pfx' }
                      a <- mkElement qn' [sattr ("xmlns:" ++ pfx') ns] cs -<< x
                      setUserState -< s
                      returnA -< a

Same problem trying to run ":t mkNSElement" in ghci.

Trac metadata

Trac field	Value
Version	6.6.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown