When trying to build the latest crux builder docker image, tagged vyos/1.2.6, I get the following error:
Step 54/59 : RUN gem install --no-document fpm ---> Running in 602ebd7990c1 ERROR: Error installing fpm: ffi requires Ruby version >= 2.3.
Reverting https://github.com/vyos/vyos-build/commit/b32a80c891ca7fe3fbe361a6c7ba5066ac9caff5 "fixes" it for me, but I'm not sure if that's a real fix or not.