typo in error msg, pointed out by Alastair Reid.
pprMatchContext PatBindRhs = ptext SLIT("In a pattern binding")
pprMatchContext LambdaExpr = ptext SLIT("In a lambda abstraction")
pprMatchContext DoExpr = ptext SLIT("In a 'do' expression pattern binding")
-pprMatchContext ListComp = ptext SLIT("In a 'list comprension' pattern binding")
+pprMatchContext ListComp = ptext SLIT("In a 'list comprehension' pattern binding")
\end{code}