linux 下 npm 安装 node-sass 错误解决

报错信息如下：

gyp verb check python checking for Python executable "python2" in the PATH
gyp verb `which` succeeded python2 /home/jjj/.pyenv/shims/python2
gyp ERR! configure error 
gyp ERR! stack Error: Command failed: /home/jjj/.pyenv/shims/python2 -c import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack pyenv: python2: command not found
gyp ERR! stack 
gyp ERR! stack The `python2' command exists in these Python versions:
gyp ERR! stack   2.7.6
gyp ERR! stack 
gyp ERR! stack 
gyp ERR! stack     at ChildProcess.exithandler (child_process.js:282:12)
gyp ERR! stack     at ChildProcess.emit (events.js:182:13)
gyp ERR! stack     at maybeClose (internal/child_process.js:947:16)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:236:5)
gyp ERR! System Linux 4.4.0-174-generic

看信息应该是 python2 没找到，我们Linux上使用pyenv 管理Python 版本，global 设置的是3.6，所以找不到 python2 ，为此我们将版本切换为2.7.6

pyenv global 2.7.6

然后再安装依赖就好了。