Re: [PATCH]: gnu: Add guile-dbi.

[iyzsong@member.fsf.org (宋文武)]

ludo@gnu.org (Ludovic Courtès) writes:

> Hi!
>
> Maurizio Boriani <baux@gnu.org> skribis:
>
>>   I'm the maintainer and first author of guile-dbi
>
> Good to see you here!  :-)
>
Oh, nice!

>>     >> Unfortunately, Guile DBI loads its backends using `dlopen', so I
>>     >> have to set 'LD_LIBRARY_PATH' to '$guile-dbd-sqlite/lib' for
>>     >> loading it.
>>
>>     Ludovic> I don’t have any great ideas.
>>
>>     Ludovic> If it uses lt_dlopen, then we should recommend setting
>>     Ludovic> LTDL_LIBRARY_PATH instead of LD_LIBRARY_PATH, which is a
>>     Ludovic> lesser evil.
>>
>>     Ludovic> Otherwise, we could also hard-code the file name of, say,
>>     Ludovic> guile-dbd-sqlite in guile-dbi, such that there’s always at
>>     Ludovic> least one backend available.
>>
>> may be ok for you if I introduce and 'hardcoded' default search path
>> for library lookup in guile-dbi source code and do a new release? 
>
> I don’t think there’s any good default search path that we could hard
> code, though, except arbitrarily choosing one of the backends as I
> suggested above.
>
> Ideas?
I think it will be great to introduce a new search path (eg: GUILE_DBD_PATH)
in addition to LD_LIBRARY_PATH.  Find the absolute so filepath in it
ourself, then pass to dlopen.  


Another idea is changing dbd libraries to scheme modules.  Then dbi will
use the '(dbi dbd mysql)' module, the module may use 'load-extension'.
So we can patch the scheme file of each dbd module.