[Haskell-cafe] no time profiling on my MacBookPro8,1

[Nicolas Frisby]

For this vanilla program

> module Main where
>
> main = print $ fib 40
>
> fib 0 = 1
> fib 1 = 1
> fib n = fib (n - 1) + fib (n - 2)

with these commands

$ ghc -prof -auto-all -rtsopts -O --make Main.hs -o Main
$ ./Main +RTS -p

all of the %time cells in the generated Main.prof file are 0.0, as is
the total time count (0.00 secs and 0 ticks). The %alloc cells seem
normal.

Andy Gill noticed that if you compile with -threaded, the %time cells
seem normal.

I scanned the GHC Trac tickets specific to Mac OS X, but saw no titles
that looked similar. Is this a known issue?

Thanks.