From the build log: x86_64-pc-linux-gnu-gcc -I. -I/usr/lib64/ruby/1.8/x86_64-linux -I/usr/lib64/ruby/1.8/x86_64-linux -I. -DJSON_GENERATOR -fPIC -march=native -O2 -g0 -pipe -fno-strict-aliasing -fPIC -Wall -O0 -ggdb -c generator.c Please also drop -ggdb
Updated the ebuild to account for changes in the build system in json-1.8.0-r1.