pyenv利用環境でのnpm installでpython2周りのエラーが出た時

~ $ npm install -g bower /Users/<user_name>/.nvm/versions/node/v4.2.1/bin/bower -> /Users/<user_name>/.nvm/versions/node/v4.2.1/lib/node_modules/bow er/bin/bower bower@1.6.5 /Users/<user_name>/.nvm/versions/node/v4.2.1/lib/node_modules/bower > bufferutil@1.2.1 install /Users/<user_name>/.nvm/version…</user_name></user_name></user_name></user_name>