current CVS version doesn't compile

[Peter Simons]

I'm trying to compile the latest version of GHC from CVS on Linux, but
the build reproducibly fails at this point:

    main/SysTools.lhs:703:
        Couldn't match `IO ExitCode' against `t -> t1'
            Expected type: IO ExitCode
            Inferred type: t -> t1
        Probable cause: `rawSystem' is applied to too many arguments in the call
            (rawSystem pgm real_args)
        In a 'do' expression: exit_code <- rawSystem pgm real_args
    make[2]: *** [stage1/main/SysTools.o] Error 1
    make[1]: *** [all] Error 1
    make[1]: Leaving directory `/usr/local/src/ghc-current/ghc'

Does anyone have an idea what's going wrong here?

Peter