问题描述如下，报没有找到mysql_config环境变量：
$ pip install mysql-python
Collecting MySQL-python==1.2.5 (from -r requirement (line 16))
Downloading MySQL-python-1.2.5.zip (108kB)
100% |################################| 112kB 56kB/s
Complete output from command python setup.py egg_info:
sh: mysql_config: command not found
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/tmp/pip-build-HVEeJz/MySQL-python/setup.py", line 17, in <module>
metadata, options = get_config()
File "setup_posix.py", line 43, in get_config
libs = mysql_config("libs_r")
File "setup_posix.py", line 25, in mysql_config
raise EnvironmentError("%s not found" % (mysql_config.path,))
EnvironmentError: mysql_config not found
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-HVEeJz/MySQL-python/
解决：
因为相关依赖没有安装。
Ubuntu/Debian：
sudo apt-get install libmysqlclient-dev