mkoctfile does not find octave/oct.h in MXE-Octave 3.8.1-5 (Windows 7, 32 bits)

[Julien Bect]

Hello all,

I have the following problem with the unofficial MXE-Octave build 
3.8.1-5 from http://mxeoctave.osuv.de <http://mxeoctave.osuv.de/>.

When I try to use mkoctfile to build the NLopt library wrapper 
(http://ab-initio.mit.edu/wiki/index.php/NLopt_on_Windows), I get :

$ mkoctfile -v -lnlopt-0 --output nlopt_optimize.oct nlopt_optimize-oct.cc
g++ -c -I/root/mxe-octave/usr/i686-w64-mingw32/include 
-I\root\mxe-octave\usr\i686-w64-mingw32\include\octave-3.8.1\octave\.. 
-I\root\mxe-octave\usr\i686-w64-mingw32\include\octave-3.8.1\octave 
-I\root\mxe-octave\usr\i686-w64-mingw32\include -mieee-fp -g -O2 
-pthread    nlopt_optimize-oct.cc -o nlopt_optimize-oct.o
nlopt_optimize-oct.cc:23:24: fatal error: octave/oct.h: No such file or 
directory
 #include <octave/oct.h>
                        ^
compilation terminated.

The problem seems to come from the include paths -I\root\mxe-octave\*.

Octave is installed in

    C:\Octave\Octave-3.8.1\

the actual location of oct.h is

    C:\Octave\Octave-3.8.1\include\octave-3.8.1\octave.

and I am on Windows 7 32 bits.

Am I doing something wrong ? Is there some manual path configuration to 
be done ? Is this a known problem ? Should I file a bug report ?

@++
Julien