> < ^ Date: Mon, 13 May 2002 09:59:27 +0100
> < ^ From: Steve Linton <sal@dcs.st-and.ac.uk >
< ^ Subject: Re: Problem with `OutputTextString' (gap4r3, Linux/IA32)

Dear GAP Forum,

Frank Heckenback wrote:

after upgrading to gap4r3, I'm having problems with the homology
package we're developing. I could trace it to the following problem:

s := ""; Process (DirectoryCurrent (), "/bin/true", InputTextNone (),
OutputTextString (s, true), []);

Error, no method found! For debugging hints type ?Recovery from
NoMethodFound Error, no 1st choice method found for `WriteAll' on 2
arguments called from WriteAll( output, ReadAll( new ) ); called from
<function>( <arguments> ) called from read-eval-loop

This seems to happen whenever the shell command produces no output.

This is indeed a bug in GAP 4.3, a case we overlooked in the substantial
overhaul of the streams machinery (now much faster in many cases) that took
place since release 4.2. A fix for this problem has been developed and Frank
confirms that it works for him. It will be included in the first bugfix for
GAP 4.3. If anyone needs it more urgently, they can obtain it from me.

	Steve Linton
Steve Linton	School of Computer Science  &
      Centre for Interdisciplinary Research in Computational Algebra
	     University of St Andrews 	 Tel   +44 (1334) 463269
http://www-theory.dcs.st-and.ac.uk/~sal	 Fax   +44 (1334) 463278   

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