Subject: Re: Issues with the wrappers
To: Krister Walfridsson <>
From: Ignatios Souvatzis <>
List: tech-pkg
Date: 07/31/2006 07:56:37
On Sun, Jul 30, 2006 at 02:47:16PM +0200, Krister Walfridsson wrote:
> I have noticed some issues with the wrappers while doing work on a package
> that compiles quite a lot of files (lang/ghc).
> 1. Too much is cached in the wrapper cache
>    Ghc use absolute paths to the files during compilation, with the
>    result that all those input/output-filenames are added to the cache,
>    and the cache has 65879 lines at end of compilation.  This is bad
>    because /bin/sh does not handle big case statements efficiently [a],
>    and each lookup consumes 0.2 seconds on my AMD Athlon 3500+ machine.
>    This adds up, and hours are spent in this case-statement during the
>    build of the package.
>    I would assume that most filenames provided to the compiler are only
>    used once, and do not need to be cached.  My suggestion is that
>    we should not add the -o options or filenames that are used as input
>    (or expressed differently, we should only add arguments that start
>    with an '-' and their arguments, unless they are the '-o' option). [b]
> 2. Too much is logged in the .wrapper.log
>    The wrappers log quite a lot of detailed information by default,
>    with the result that my .work.log file is 176236028 bytes.
>    The wrapper functionality is mature, so this detailed information
>    is seldom needed, and you can in general determine what happened
>    by looking at the input/output-lines (i.e. those lines marked as "[*]"
>    and "<.>" in the .work.log).  I would therefore like to change the
>    default behavior to only log the input/output-lines.
> Comments?

Whatever speeds up building of ghc is good.

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