Re: [PATCH] Don't augment LD_LIBRARY_PATH (was Re: [PATCH] do not augment environment)

[ludo@gnu.org (Ludovic Courtès)]

Hi,

Mark H Weaver <mhw@netris.org> skribis:

> I wrote:
>> I've read the message referenced above several times, but I've failed to
>> understand why we cannot use 'lt_dladdsearchdir' to augment the path, as
>> shown in the first code excerpt of that message:
>>
>>   env = getenv ("GUILE_SYSTEM_EXTENSIONS_PATH");
>>
>>   [...]
>>
>>   if (env)
>>     lt_dladdsearchdir (env);
>>   else
>>     {
>>       lt_dladdsearchdir (SCM_LIB_DIR);
>>       lt_dladdsearchdir (SCM_EXTENSIONS_DIR);
>>     }
>
> Actually, I can already see a problem with this.  SCM_LIB_DIR is usually
> (always?) already present in the library search paths before Guile is
> initialized.  It is set to $(libdir) by libguile/Makefile.  Isn't
> $(libdir) where libguile is installed?

In 1.8 and earlier, extensions were installed under $libdir, and it’s
just an obvious convenience to ensure that $libdir is in the search
path.

Note that lt_dladdsearchdir /appends/ its arguments to the search path.

[...]

> With this in mind, I now propose the following:
>
>   env = getenv ("GUILE_SYSTEM_EXTENSIONS_PATH");
>   if (env)
>     lt_dladdsearchdir (env);
>   else
>     lt_dladdsearchdir (SCM_EXTENSIONS_DIR);
>
> and then to run the uninstalled guile, we'd need to set (or augment) one
> of the *_LIBRARY_PATH environment variables to point within the build
> directory, and also set GUILE_SYSTEM_EXTENSIONS_PATH.
>
> What do you think?

First, I think we don’t want to change the behavior at all in 2.0,
because that’s a sure way to surely get reports of angry users.

Other than that, in 2.1 we could consider dropping $libdir like this,
and making sure all extensions get installed in the right place.  That
would probably make sense.

> On a related topic, why is libguilereadline-v-18.* installed in
> SCM_LIB_DIR and not SCM_EXTENSIONS_DIR?

Historical reasons.  We should probably change it in 2.1, and also
remove the “lib” prefix.

WDYT?

Ludo’.