Re: how to use libraries in /usr/local

[Thomas E. Dickey]

On Mon, 21 May 2001, Bruno Haible wrote:

> So, in fact, it is a problem with *most* platforms, excluding GNU.
> This is also what is written in the GNU standards:
>
>      Most compilers other than GCC do not look for header files in
>      directory `/usr/local/include'.  So installing the header files
>      this way is only useful with GCC.  Sometimes this is not a problem
>      because some libraries are only really intended to work with GCC.
>      But some libraries are intended to work with other compilers.
>      They should install their header files in two places, one
>      specified by `includedir' and one specified by `oldincludedir'.
>
> Note that oldincludedir = /usr/include. I haven't seen a single
> package following this advice to install header files both in
> /usr/include and /usr/local/include (fortunately - because I can
> imagine the mess this can lead to).

sure (for example, ncurses on Solaris).

but making gcc look _first_ in /usr/local/include is a design defect,
which unfortunately won't go away in the forseeable future.

>
> The objective is to make installed GNU libraries easily available to
> other packages during configuration.
>
> I would like to propose a "configure" option --use-local which,
> depending on the language being used, does the following. For C and
> C++, it appends " -I/usr/local/include" to CPPFLAGS and
> " -L/usr/local/lib" to LDFLAGS. For Fortran, it should do similar
> things.

at first glance, it sounds like a good thing, but it won't work, since
on many platforms, /usr/local isn't used for the programs that you're
attempting to fix.

-- 
T.E.Dickey <address@hidden>
http://dickey.his.com
ftp://dickey.his.com