No settings file found or unable to load settings files

[plmday]

Hi,

I am curious to try Logtalk out. I followed the installation instruction and it installed successfully. But when I tried to run it, I get the following:

Code: Select all

$ bplgt

B-Prolog Version 7.8#5, All rights reserved, (C) Afany Software 1994-2013.

Type 'help' for usage.
consulting::/home/day/apps/logtalk/share/logtalk/integration/logtalk_bp.pl
Compiling::/home/day/apps/logtalk/share/logtalk/adapters/b.pl
compiled in 7 milliseconds
loading::/home/day/apps/logtalk/share/logtalk/adapters/b.out
Compiling::/home/day/apps/logtalk/share/logtalk/paths/paths.pl
compiled in 3 milliseconds
loading::/home/day/apps/logtalk/share/logtalk/paths/paths.out
Compiling::/home/day/apps/logtalk/share/logtalk/core/core.pl
compiled in 440 milliseconds
loading::/home/day/apps/logtalk/share/logtalk/core/core.out
Compiling::/home/day/.logtalk/scratch/core_messages.pl
compiled in 10 milliseconds
loading::/home/day/.logtalk/scratch/core_messages.out
Compiling::/home/day/.logtalk/scratch/expanding.pl
compiled in 0 milliseconds
loading::/home/day/.logtalk/scratch/expanding.out
Compiling::/home/day/.logtalk/scratch/monitoring.pl
compiled in 0 milliseconds
loading::/home/day/.logtalk/scratch/monitoring.out
Compiling::/home/day/.logtalk/scratch/forwarding.pl
compiled in 0 milliseconds
loading::/home/day/.logtalk/scratch/forwarding.out

Logtalk 3.0.0
Copyright (c) 1998-2013 Paulo Moura

% Default lint compilation flags: 
%   unknown_entities: warning, misspelt_calls: warning
%   portability: silent
%   missing_directives: warning, redefined_built_ins: silent
%   singleton_variables: warning, underscore_variables: singletons
% Default optional features compiler flags:
%   complements: deny, dynamic_declarations: deny
%   context_switching_calls: allow, events: deny
% Other default compilation flags:
%   report: on, scratch_directory: ./.lgt_tmp/
%   code_prefix: $, hook: (none defined)
%   optimize: off, source_data: on, clean: on
%   debug: off
% Back-end Prolog compiler flags:
%   prolog_compiler: []
%   prolog_loader:   []
% Read-only compilation flags (back-end Prolog compiler features):
%   prolog_dialect: b, modules: unsupported, threads: unsupported
%   encoding_directive: unsupported, tabling: supported, coinduction: unsupported
% 
*     No settings file found or unable to load settings files due to file
*     system access limitations of the back-end Prolog compiler.

I did not get the error message at the end. I tried several other backends (swi-prolog, yap and xsb) and got the same error message. Any idea what is wrong?

[Paulo Moura]

Nothing is wrong; it's just a warning that you can ignore. The Logtalk runtime could not find any "settings.lgt" file on the startup directory or in the $LOGTALKUSER directory. This means that the default value for the compiler flags, as defined in the adapter file for your back-end Prolog compiler will be used. There's a "settings-sample.lgt" in the $LOGTALKUSER directory that you can rename and customize (see the comments on file itself).

Thanks for trying Logtalk. Enjoy.

[plmday]

Thanks for the answer, Paolo. If it is a warning, it may be good to actually indicate that in the message, like "Warning: No settings file found ...".

[Paulo Moura]

By default, informative messages use a "%" line prefix, warnings use a "*" line prefix, and errors use a "!" line prefix. It's a practice originated in Quintus Prolog and used in Logtalk and several Prolog compilers. Settings file are handy but optional and otherwise emphasizing the warning nature of the message could be more misleading. The bit that I really don't like is the "or unable to load settings files due to file system access limitations of the back-end Prolog compiler". It's an unfortunate consequence of the lack of strong Prolog standards. Removing it would allow to turn this warning into a mere informative message.