Question

I have a weird problem with SWI Prolog 6.2.0 and XPCE on Unix.

When I run a prolog program, it works perfectly fine.

swipl -f file.pl

However, whenever I try and compile the same program

swipl -o launch -c file.pl

I get an error telling me that pce library is not available

source_sink `library(pce)' does not exist

I am completely lost as for what could be the reason . . .

Answer 1

I’ve tried to compile colour.pl, a sample from XPCE manual, and I found the same problem you report. Seems that’s mandatory to specify the XPCE library path.

I was able to compile with

swipl -p library=~/lib/swipl-6.1.13/xpce/prolog/lib/ -o colour -c colour.pl

Obtaining the library path is not immediate: the easy way I found: open the source of your file, at line of the first error message (should be something like :- use_module(library(pce)).) with the IDE.
Then with the right mouse button open the library source, and from menu File click Save as..., the box will show the path you can use to compile.

HTH