From solovay at Math.Berkeley.EDU  Sun May 21 06:31:48 2006
From: solovay at Math.Berkeley.EDU (Robert M. Solovay)
Date: Sun May 21 06:25:10 2006
Subject: [nhc-users] Trouble with NHC?
Message-ID: <Pine.GSO.4.63.0605210329080.23808@blue3>


I am trying to compile the following simple program:

module Main where
import System.Environment

main :: IO ()
main = do args <- getArgs
           putStrLn ("Hello, " ++ args !! 0)

I get the following error message:

solovay@chaos Haskell_Scheme]$ nhc98 program1.hs
I/O error (user-defined), call to function `userError':
   Can't open any of:
  ./System/Environment.hi
  /usr/local/include/nhc98/packages/base/System/Environment.hi
  /usr/local/include/nhc98/System/Environment.hi
  when trying to read System.Environment.

 	Have I installed nhc98 incorrectly? Or what is it I'm doing wrong?

 	Thanks,

 	--Bob Solovay


From Malcolm.Wallace at cs.york.ac.uk  Sun May 21 10:16:33 2006
From: Malcolm.Wallace at cs.york.ac.uk (Malcolm Wallace)
Date: Sun May 21 10:09:39 2006
Subject: [nhc-users] Trouble with NHC?
In-Reply-To: <Pine.GSO.4.63.0605210329080.23808@blue3>
References: <Pine.GSO.4.63.0605210329080.23808@blue3>
Message-ID: <20060521151633.4a677906.Malcolm.Wallace@cs.york.ac.uk>

"Robert M. Solovay" <solovay@Math.Berkeley.EDU> writes:

> $ nhc98 program1.hs
> I/O error (user-defined), call to function `userError':
>    Can't open any of:
>   ./System/Environment.hi
>   /usr/local/include/nhc98/packages/base/System/Environment.hi
>   /usr/local/include/nhc98/System/Environment.hi
>   when trying to read System.Environment.
> 
> Have I installed nhc98 incorrectly? Or what is it I'm doing wrong?

It certainly looks like the installation was incomplete.  The interface
file for System.Environment ought to live in 
    /usr/local/include/nhc98/packages/base/System/Environment.hi

How did you install nhc98?  If you built it with a C compiler, it is
possible that you need to download and install the extra interface
files for the hierarchical libraries (available at the bottom of the
download web page):
    http://haskell.org/nhc98/download.html
These were accidentally omitted from the main package (they are normally
built afresh at build time if you bootstrap with a Haskell compiler
instead of via C).

On the other hand, if only some interface files are missing from
    /usr/local/include/nhc98/packages/base/
rather than all of them, then there may have been a compile error at
build time, in which case it would be useful to rebuild and capture the
error message.

Regards,
    Malcolm