I'm trying to use ruby on a Raspberry Pi with the ruby-opencv gem - but alas it will not build :(
root@raspberrypi:/usr/lib# uname -a
Linux raspberrypi 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux
root@raspberrypi:/usr/lib# ruby -v
ruby 2.1.5p273 (2014-11-13) [arm-linux-gnueabihf]
root@raspberrypi:~# apt-get install libopencv-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
libopencv-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
root@raspberrypi:~# apt-get install libopencv-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
libopencv-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
root@raspberrypi:~# gem install ruby-opencv
Fetching: ruby-opencv-0.0.18.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing ruby-opencv:
ERROR: Failed to build gem native extension.
/usr/local/bin/ruby extconf.rb
>> Check the required libraries...
checking for main() in -lstdc++... yes
checking for main() in -lopencv_calib3d... yes
checking for main() in -lopencv_contrib... yes
checking for main() in -lopencv_core... yes
checking for main() in -lopencv_features2d... yes
checking for main() in -lopencv_flann... yes
checking for main() in -lopencv_highgui... yes
checking for main() in -lopencv_imgproc... yes
checking for main() in -lopencv_legacy... yes
checking for main() in -lopencv_ml... yes
checking for main() in -lopencv_objdetect... yes
checking for main() in -lopencv_video... yes
checking for main() in -lopencv_photo... yes
checking for main() in -lopencv_gpu... yes
checking for main() in -lopencv_nonfree... no
opencv_nonfree not found.
>> Check the required headers...
checking for opencv2/core/core_c.h... yes
checking for opencv2/core/core.hpp... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/bin/ruby
--with-opencv-dir
--without-opencv-dir
--with-opencv-include
--without-opencv-include=${opencv-dir}/include
--with-opencv-lib
--without-opencv-lib=${opencv-dir}/lib
--with-libxml2-dir
--without-libxml2-dir
--with-libxml2-include
--without-libxml2-include=${libxml2-dir}/include
--with-libxml2-lib
--without-libxml2-lib=${libxml2-dir}/lib
--with-stdc++lib
--without-stdc++lib
--with-opencv_calib3dlib
--without-opencv_calib3dlib
--with-opencv_contriblib
--without-opencv_contriblib
--with-opencv_corelib
--without-opencv_corelib
--with-opencv_features2dlib
--without-opencv_features2dlib
--with-opencv_flannlib
--without-opencv_flannlib
--with-opencv_highguilib
--without-opencv_highguilib
--with-opencv_imgproclib
--without-opencv_imgproclib
--with-opencv_legacylib
--without-opencv_legacylib
--with-opencv_mllib
--without-opencv_mllib
--with-opencv_objdetectlib
--without-opencv_objdetectlib
--with-opencv_videolib
--without-opencv_videolib
--with-opencv_photolib
--without-opencv_photolib
--with-opencv_gpulib
--without-opencv_gpulib
--with-opencv_nonfreelib
--without-opencv_nonfreelib
extconf.rb:63:in `block in <main>': opencv2/core/core.hpp not found. (RuntimeError)
from extconf.rb:63:in `each'
from extconf.rb:63:in `<main>'
Gem files will remain installed in /usr/local/lib/ruby/gems/2.0.0/gems/ruby-opencv-0.0.18 for inspection.
Results logged to /usr/local/lib/ruby/gems/2.0.0/gems/ruby-opencv-0.0.18/ext/opencv/gem_make.out
root@raspberrypi:~#
