magic.mgk not found [WAS: Re: Issues & questions building Octave-3.4.2 MinGW]

[Philip Nienhuis]

Hi Tatsuro,

Picking up again on MinGW.
Reviving a post from July 9th...

Tatsuro MATSUOKA wrote:
> Hello
>
> --- On Sun, 2011/7/10, Philip Nienhuis  wrote:
<snip>
> > As to the tests, the three unexpected FAILs are in:
> > - imread.m
> > "imread: invalid image file: Magick++ exception: Magick: Unable to access 
> > configuration file (magic.mgk) reported by magick/blob.c:1830 (GetConfigureBlob)"
>
> Hmmm. I have never seen this error.

Could it be that you don't see this because you have your GraphicsMagick 
development in place, so that GraphicsMagick knows where to find its 
config file on your system?

I tried with your binary; unzipped it, started Octave, and entered

  test imread

to get the same error. Indeed, a search in the unzipped binary tree 
shows no trace of magic.mgk.


In the 3.2.4 MinGW binary it is in /share/GraphicsMagick/config/

Benjamin made some patches to GraphicsMagick to fix this issue for 
Octave-3.2.0, see here:

http://octave.1599824.n4.nabble.com/imread-on-Octave-3-2-0-for-Windows-td1636683.html 


and here:

http://octave.svn.sourceforge.net/viewvc/octave/trunk/octave-forge/admin/Windows/mingw32/graphicsmagick/GraphicsMagick-1.3.12-5.patch?revision=8447&content-type=text%2Fplain

(line wrap!)  The relevant patch for blob.c starts around L. 47. I've 
seen this code snippet elsewhere when googling for solutions.

The error can also be circumvented by adding a setenv statement in octaverc:
setenv ("MAGICK_CONFIGURE_PATH", "/full/path/to/magic.mgk")

Philip