Add note about annoying MySQL Connector bug. (PyMySQL#212)

gvoysey · methane · commit d65e10e35603 · 2017-12-21T18:41:31.000+09:00
diff --git a/README.md b/README.md
@@ -13,19 +13,44 @@ I hope this fork is merged back to MySQLdb1 like distribute was merged back to s
 
 You may need to install the Python and MySQL development headers and libraries like so:
 
-`sudo apt-get install python-dev libmysqlclient-dev`  # Debian / Ubuntu
+* `sudo apt-get install python-dev libmysqlclient-dev`  # Debian / Ubuntu
+* `sudo yum install python-devel mysql-devel`  # Red Hat / CentOS
+* `brew install mysql-connector-c`  # macOS (Homebrew)  (Currently, it has bug. See below)
 
-`sudo yum install python-devel mysql-devel`  # Red Hat / CentOS
-
-On Windows, there are binary wheel you can install without MySQLConnector/C or MSVC. 
+On Windows, there are binary wheels you can install without MySQLConnector/C or MSVC. 
 
 #### Note on Python 3 : if you are using python3 then you need to install python3-dev using the following command :
 
 `sudo apt-get install python3-dev` # debian / Ubuntu
 
 `sudo yum install python3-devel `  # Red Hat / CentOS
 
-`brew install mysql-connector-c`  # macOS (Homebrew)
+#### **Note about bug of MySQL Connector/C on macOS**
+
+See also: https://bugs.mysql.com/bug.php?id=86971
+
+Versions of MySQL Connector/C may have incorrect default configuration options that cause compilation errors when `mysqlclient-python` is installed.  (As of November 2017, this is known to be true for homebrew's `mysql-connector-c` and [official package](https://dev.mysql.com/downloads/connector/c/))
+
+Modification of `mysql_config` resolves these issues as follows. 
+
+Change
+
+```
+# on macOS, on or about line 112:
+# Create options 
+libs="-L$pkglibdir"
+libs="$libs -l "
+```
+
+to 
+
+```
+# Create options 
+libs="-L$pkglibdir"
+libs="$libs -lmysqlclient -lssl -lcrypto"
+```
+
+An improper ssl configuration may also create issues; see, e.g, `brew info openssl` for details on macOS.
 
 ### Install from PyPI
 
diff --git a/setup_posix.py b/setup_posix.py
@@ -9,6 +9,8 @@
 # of mysql_config
 
 def dequote(s):
+    if not s:
+        raise Exception("Wrong MySQL configuration: maybe https://bugs.mysql.com/bug.php?id=86971 ?")
     if s[0] in "\"'" and s[0] == s[-1]:
         s = s[1:-1]
     return s
