Manjaro can't compile OPENCV example

buenas
i fix the other manajaro error but now im trying to compile any of the OPENCv Examples and i get this

PKG_CONFIG_LIBDIR=
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing opencv.pc' to the PKG_CONFIG_PATH environment variable Package 'opencv', required by 'virtual:world', not found Package opencv was not found in the pkg-config search path. Perhaps you should add the directory containingopencv.pc’
to the PKG_CONFIG_PATH environment variable
Package ‘opencv’, required by ‘virtual:world’, not found
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing opencv.pc' to the PKG_CONFIG_PATH environment variable Package 'opencv', required by 'virtual:world', not found Package opencv was not found in the pkg-config search path. Perhaps you should add the directory containingopencv.pc’
to the PKG_CONFIG_PATH environment variable
Package ‘opencv’, required by ‘virtual:world’, not found
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing opencv.pc' to the PKG_CONFIG_PATH environment variable Package 'opencv', required by 'virtual:world', not found Package opencv was not found in the pkg-config search path. Perhaps you should add the directory containingopencv.pc’
to the PKG_CONFIG_PATH environment variable
Package ‘opencv’, required by ‘virtual:world’, not found
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv.pc’
to the PKG_CONFIG_PATH environment variable
Package ‘opencv’, required by ‘virtual:world’, not found
Compiling /home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample/src/ofApp.cpp
g++ -c -O3 -march=native -mtune=native -DNDEBUG -Wall -Werror=return-type -std=c++14 -DGCC_HAS_REGEX -DOF_USING_GTK -DOF_USING_GTK -DOF_USING_MPG123 -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/fmodex/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include/glm -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include/glm/gtc -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include/glm/detail -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include/glm/gtx -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/glm/include/glm/simd -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/json/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/kiss/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/pugixml/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/tess2/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/utf8/include -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/utf8/include/utf8 -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/communication -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/math -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/utils -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/events -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/video -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/sound -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/gl -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/graphics -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/types -I/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/app -I/home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample/src -I/home/jacos/of_v0.10.1_linux64gcc6_release/addons/ofxOpenCv/src -I/home/jacos/of_v0.10.1_linux64gcc6_release/addons/ofxOpenCv/libs -MMD -MP -MF obj/linux64/Release/src/ofApp.d -MT obj/linux64/Release/src/ofApp.o -o obj/linux64/Release/src/ofApp.o -c /home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample/src/ofApp.cpp
In file included from /home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/ofMain.h:65,
from /home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample/src/ofApp.h:3,
from /home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample/src/ofApp.cpp:1:
/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/graphics/ofCairoRenderer.h:4:10: fatal error: cairo.h: No such file or directory
#include “cairo.h”
^~~~~~~~~
compilation terminated.
make[1]: *** [/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworksCompiled/project/makefileCommon/compile.project.mk:223: obj/linux64/Release/src/ofApp.o] Error 1
make[1]: Leaving directory ‘/home/jacos/of_v0.10.1_linux64gcc6_release/examples/computer_vision/opencvExample’
make: *** [/home/jacos/of_v0.10.1_linux64gcc6_release/libs/openFrameworksCompiled/project/makefileCommon/compile.project.mk:129: Release] Error 2

and i do have installed opencv for what i can see

can you try using the nightly builds? all this problems have been already fixed but we haven’t done a release yet

i think i got the nightly vs, let me check tonight but that maybe i should downgrade OpenCv from 4 to 3 ?

no, nightlies should work with any of opencv 4 or 3. from your path it really seems you have OF 0.10.1 not the nightly build