catalogic-msgc to build, install flex 2.6.4 into flex-2.6.4 subdirectory, then run make (should work on Linux): wget https://github.com/westes/flex/releases/download/v2.6.4/flex-2.6.4.tar.gz -O - | tar -zxvf - cd flex-2.6.4 ./configure make cd .. make