Message d'avertissement lors de l'exécution de brew list

Quand je cours brew list sur mon Mac OS X EI Capitan, il me donnera toujours un message d'erreur comme celui-ci : --

$ brew list
/bin/sh: __rvm_ruby_string_find: line 8: syntax error near unexpected token `('
/bin/sh: __rvm_ruby_string_find: line 8: ` ruby-+([1-9]) | ruby-+([1-9]).+([0-9]) | ruby-1.+([1-9]).+([0-9]) | jruby-[19]*)'
/bin/sh: error importing function definition for `__rvm_ruby_string_find'
/bin/sh: __rvm_project_ruby_env_load_parse_file: line 9: syntax error near unexpected token `('
/bin/sh: __rvm_project_ruby_env_load_parse_file: line 9: ` __rvm_read_lines __variables <( { cat "$1"; echo ""; } | __rvm_sed "${__sed_commands[@]}" )'
/bin/sh: error importing function definition for `__rvm_project_ruby_env_load_parse_file'
/bin/sh: __rvm_remove_without_gems: line 2: syntax error near unexpected token `('
/bin/sh: __rvm_remove_without_gems: line 2: ` __rvm_read_lines __gems_to_remove <('
/bin/sh: error importing function definition for `__rvm_remove_without_gems'
gdbm        openssl     python      readline    sqlite

Image Lien

Chaque fois que je lance rvm, je reçois le même message d'erreur.

$ rvm
bash: __rvm_ruby_string_find: line 8: syntax error near unexpected token `('
bash: __rvm_ruby_string_find: line 8: ` ruby-+([1-9]) | ruby-+([1-9]).+([0-9]) | ruby-1.+([1-9]).+([0-9]) | jruby-[19]*)'
bash: error importing function definition for `__rvm_ruby_string_find'

Comment puis-je le résoudre ? Merci !