"ld: atom sorting error for ..." on OS X

I'm seeing atom sorting errors while building GHC on OS X, e.g.:

Configuring ghc-bin-6.9...
/Users/ian/ghc/darcs/val/libraries/cabal-bin /usr/bin/ghc /Users/ian/ghc/darcs/val/libraries/bootstrapping.conf build     --distpref dist-stage2 
Preprocessing executables for ghc-bin-6.9...
Building ghc-bin-6.9...
[1 of 1] Compiling Main             ( Main.hs, dist-stage2/build/ghc/ghc-tmp/Main.o )
Linking dist-stage2/build/ghc/ghc ...
ld: atom sorting error for _ghczm6zi9_LibFFI_Czuffizutype_closure_tbl and _ghczm6zi9_LibFFI_Czuffizucif_closure_tbl in /Users/ian/ghc/darcs/val/compiler/dist-stage2/build/libHSghc-6.9.a(LibFFI.o)
ld: atom sorting error for _ghczm6zi9_LibFFI_Czuffizutype_closure_tbl and _ghczm6zi9_LibFFI_Czuffizucif_closure_tbl in /Users/ian/ghc/darcs/val/compiler/dist-stage2/build/libHSghc-6.9.a(LibFFI.o)

It doesn't seem to cause any problems, but it's a little worrying.

Trac metadata

Trac field	Value
Version	6.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown