Probably not a bug ... rather user manual omission.

[David Plume]

ghc-3.10, Solaris 2.5.1

The compiler doesn't appear to link programs compiled with the
-prof -auto options if the -O flag is set. 

As far as I can make out that's just fine, as long as it says
so in the 'Compiling programs for profiling' section of the user
manual - but I couldn't find it.

Can send more info if you like ...

   Cheers,

     Dave