below is currently only available in the GHC runtime system when the runtime system
has been compiled using a special option.
-When recompiling GHC, use ./configure --enable-threaded-rts to enable this.
+When recompiling GHC, use .\/configure --enable-threaded-rts to enable this.
To find your GHC has already been compiled that way, use
'rtsSupportsBoundThreads' from GHCi.