Re: how to use gsl with the guile ffi

[Matt Wette]

tantalum <address@hidden> writes:
> > im getting the error "In procedure dynamic-link: file: "libgsl",
> > message: "file not found"" with the following code:
> >
> >       (import (system foreign))
> >       (define gsl (dynamic-link "libgsl"))
> >
> > * gsl (optionally?) depends on libgslcblas, which itself links without
> > error, but loading it with (dynamic-link) beforehand did not help
> > * some libraries work, for example libmagic. libm for example gives the
> > same error message
> > * the file /usr/lib/libgsl.so exists and is a symlink to the regular
> > file libgsl.so.23.1.0 whose content begins with ELF>
> > * similar problem on the mailing list
> > https://lists.gnu.org/archive/html/guile-user/2016-05/msg00010.html
> > * ive tried to set LD_LIBRARY_PATH with export to /usr/lib with no
> > apparent effect
> > * i was going from this manual entry
> > https://www.gnu.org/software/guile/manual/html_node/Dynamic-FFI.html
> > * guile (GNU Guile) 2.2.4
> >
> > the issue can actually be reproduced with a c program:
> >
> >       #include <dlfcn.h>
> >       #include <stdio.h>
> >
> >       int main () {
> >         void* a = dlopen("libgsl.so", RTLD_NOW);
> >         printf("got %p\n", a);
> >         if (a) printf("ok\n"); else printf("error: %s\n", dlerror());
> >       }
> >
> > gcc t.c -ldl && ./a.out
> >
> > the program only works without error when compiled with -lgslcblas.
> > so, it could be a more basic issue, but i dont know how to proceed.

I see this often enough.  It is not a Guile issue.  Your runtime needs to know
where to find the .so file.  Typically you can fix this problem by setting
LD_LIBRARY_PATH prior to "guile".  For HDF5 I need to ...
$ LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/hdf5/serial
$ export LD_LIBRARY_PATH
$ guile hdf5demo.scm
...