corrígem update --system pensando que resolvería un problema que estaba teniendo, y ahora no puedo correrrails server. No se carga y en su lugar, sigo recibiendo lo siguiente. ¿Alguien puede decirme cómo deshacer esto y volver antes de ejecutar la actualización?

Ya he corridogit checkout, pero el problema persiste ...

/usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/bundler-1.1.5/lib/bundler/rubygems_integration.rb:187:in `stub_source_index170': uninitialized constant Gem::SourceIndex (NameError)
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/bundler-1.1.5/lib/bundler/rubygems_integration.rb:353:in `stub_rubygems'
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/bundler-1.1.5/lib/bundler/rubygems_integration.rb:250:in `replace_entrypoints'
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/bundler-1.1.5/lib/bundler/runtime.rb:14:in `setup'
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/bundler-1.1.5/lib/bundler.rb:107:in `setup'
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/rubygems-bundler-1.0.7/lib/rubygems-bundler/noexec.rb:66:in `setup'
from /usr/local/rvm/gems/ruby-1.9.3-p194@global/gems/rubygems-bundler-1.0.7/lib/rubygems-bundler/noexec.rb:78:in `<top (required)>'
from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:110:in `require'
from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:110:in `rescue in require'
from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:35:in `require'
from /usr/local/rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:9:in `<main>'