final revision to GArrow classes

[ghc-base.git] / Debug / Trace.hs

diff --git a/Debug/Trace.hs b/Debug/Trace.hs
index c30c811..ebacb6c 100644 (file)
--- a/Debug/Trace.hs
+++ b/Debug/Trace.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP, ForeignFunctionInterface #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Debug.Trace
@@ -41,7 +43,9 @@ putTraceMsg msg = do
      withCString msg  $ \cmsg ->
       debugBelch cfmt cmsg
 
-foreign import ccall unsafe "RtsMessages.h debugBelch"
+-- don't use debugBelch() directly, because we cannot call varargs functions
+-- using the FFI.
+foreign import ccall unsafe "HsBase.h debugBelch2"
    debugBelch :: CString -> CString -> IO ()
 #endif