Ruby Gem install Json fails on Mavericks and Xcode 5.1 - unknown argument: '-multiply_definedsuppress'

Question

I was trying run gem install json and got the following error

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /System/Library/Framewo         


        

Answer 1

It's been a while and I've got similar error. An alternative to folks using bundler is to add the flag to the build configuration like below example:

bundle config build. --with-cflags="-Wno-error=implicit-function-declaration"

followed by

bundle install

Please note that you must replace above with the name of the actual gem that is throwing the error while building native extensions.

I hope this becomes helpful to others that face similar issues in the future!