Re: weird problem with __magick_read__.oct

[John W. Eaton]

On 15-Jul-2009, John W. Eaton wrote:

| On  5-Jul-2009, Andy1978 wrote:
| 
| | John W. Eaton-3 wrote:
| | > 
| | > I recently noticed that imread wasn't working for me.  Looking closer,
| | > I found that __magick_read__ was not defined.  Trying "help
| | > __magick_read__" produced the error
| | > 
| | >   error: help: `__magick_read__' not found
| | > ....
| | > Can anyone else reproduce this problem?
| | > jwe
| | > 
| | 
| | I have exactly the same problem with the latest development sources 3.1.55
| | debian sid Linux version 2.6.26-1-686 (Debian 2.6.26-13lenny2)
| | (address@hidden) (gcc version 4.1.3 20080704 (prerelease) (Debian
| | 4.1.2-25)) #1 SMP Fri Mar 13 18:08:45 UTC 2009
| | GraphicsMagick-config --version: 1.3.5
| | gcc -v: gcc version 4.3.3 (Debian 4.3.3-13)
| | 
| | How can I help to track down the problem?
| 
| If you can find out why dlopen/dlsym fails to find the function if it
| is named __magick_read__ but succeeds if the name is something else,
| then that might be a start.

This was probably bad advice, as I seem to have misremembered the
symptoms.  Anyway, please try the following change:

  http://hg.savannah.gnu.org/hgweb/octave/rev/db08c2376970

It seems that the --ldflags option for Magick++-config produces

  -L/usr/lib -Wl,-z,relro -pie -L/usr/lib/X11 -L/usr/lib -L/usr/lib

on my system.  Passing "-pie" to g++ was apparently the problem.

jwe