Confused about enabling parallel ghc

[Albert Lai]

I installed ghc 4.08.2 binaries for sparc solaris (and those for intel
linux, too), then tried compiling a sample program (the fibonacci one
in the user guide) with ghc -parallel.  The compiler complained:

    Could not find interface file for `Prelude'
    in the directories ./*.hi
                       /u/trebla/lib/ghc-4.08.2/imports/lang/*.mp_hi
                       /u/trebla/lib/ghc-4.08.2/imports/concurrent/*.mp_hi
                       /u/trebla/lib/ghc-4.08.2/imports/lang/*.mp_hi
                       /u/trebla/lib/ghc-4.08.2/imports/concurrent/*.mp_hi
                       /u/trebla/lib/ghc-4.08.2/imports/std/*.mp_hi

(and similarly for Parallel.)

Does it mean I must build ghc myself from source?

The user guide promises a lot of binary bundles such as par.  Ever
since 4.0x, the ghc download page ceases to mention them.  Where
are they?