id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
3813,Invalid warning from GHCi,NeilMitchell,igloo,"{{{
C:\Neil>ghci -Wall
GHCi, version 6.10.3.20090530: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking ... done.
Prelude> x <- return True

<interactive>:1:0: Warning: Defined but not used: `x'
Prelude> x
True
Prelude>
}}}

This error comes up in practice when writing .ghci files, for example for HLint. The user who reported it to me was running GHC 6.12.1.
",bug,closed,normal,6.12.2,GHCi,6.10.4,fixed,,,Unknown/Multiple,Unknown/Multiple,Incorrect warning at compile-time,,,,,