Linux Dialogs are not working

[yupswing]

All the dialogs on linux give Segmentation fault

I've tried to get the git repository and build again but I get this error

> haxe run hxcpp build.xml
g++ -I./src "$(pkg-config --libs --cflags gtk+-2.0)" "$(pkg-config --libs --cflags gconf-2.0)" -c -fvisibility=hidden -O2 -fpic -fPIC -DHX_LINUX -DHXCPP_VISIT_ALLOCS -DHXCPP_API_LEVEL=0 -m32 -I/usr/lib/haxe/lib/hxcpp/3,2,37/include -x c++ -frtti -Wno-invalid-offsetof ./src/api.cpp -oobj/linux/6bf1c3fc_api.o
g++: error: $(pkg-config --libs --cflags gtk+-2.0): No such file or directory
g++: error: $(pkg-config --libs --cflags gconf-2.0): No such file or directory
Error: error running g++ -I./src "$(pkg-config --libs --cflags gtk+-2.0)" "$(pkg-config --libs --cflags gconf-2.0)" -c -fvisibility=hidden -O2 -fpic -fPIC -DHX_LINUX -DHXCPP_VISIT_ALLOCS -DHXCPP_API_LEVEL=0 -m32 -I/usr/lib/haxe/lib/hxcpp/3,2,37/include -x c++ -frtti -Wno-invalid-offsetof ./src/api.cpp -oobj/linux/6bf1c3fc_api.o