Quando você rubyinstalou com rbenve tem o seguinte erro ao iniciarspring rails c
lib/spring/sid.rb:17:in `fiddle_func': uninitialized constant Spring::SID::DL (NameError)Tudo que você precisa é reinstalar o ruby com este patch:
ruby-install -p https://gist.githubusercontent.com/caius/10452604/raw/acd421a8461f4d776a8f752663db19e321f850e0/ext_dl_extconf_rb.patch ruby *your version here*Ou rbenvversão deste:
rbenv install --patch 1.9.3-p551 < <(curl -sSL https://gist.githubusercontent.com/caius/10452604/raw/acd421a8461f4d776a8f752663db19e321f850e0/ext_dl_extconf_rb.patch)Agradecimentos a: https://github.com/rails/spring/issues/274#issuecomment-40185955