最近在升幾台 FreeBSD 機器的 ports，結果發現有好幾台 php-mysql[i] 都升不過，一開始不以為意，想說可能是該 port 有錯誤，過幾天再升級就會好；不過…這次實在等太久了，於是就仔細地試著查一下是什麼原因。

本來用 portsupgrade 升級時的錯誤訊息大概是這樣的：

...
checking for mysql_close in -lmysqlclient... no
checking for mysql_error in -lmysqlclient... no
configure: error: mysql configure failed. Please check config.log for more information.
===> Script "configure" failed unexpectedly.
Please report the problem to ale@FreeBSD.org [maintainer] and attach the
"/usr/ports/databases/php5-mysql/work/php-5.2.6/ext/mysql/config.log" including
the output of the failure of your make command. Also, it might be a good idea
to provide an overview of all packages installed on your system (e.g. an `ls
/var/db/pkg`).
*** Error code 1

Stop in /usr/ports/databases/php5-mysql.
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade.80506.2 env UPGRADE_TOOL=portupgrade UPGRADE_PORT=php5-mysql-5.2.5_1 UPGRADE_PORT_VER=5.2.5_1 make
** Fix the problem and try again.
...

再往訊息裡的 log 檔 (“/usr/ports/databases/php5-mysql/work/php-5.2.6/ext/mysql/config.log”) 去找，發現了這個疑似是原因的問題：
...
configure:4201: result: no
configure:4411: checking for mysql_error in -lmysqlclient
configure:4446: cc -o conftest -O2 -fno-strict-aliasing -pipe -R/usr/local/lib/mysql -L/usr/local/lib/mysql conftest.c -lmysqlclient >&5
/usr/local/lib/mysql/libmysqlclient.so: undefined reference to `__h_error'
configure:4452: $? = 1
...

看起來就像是 MySQL client library (的版本?)有問題，導致出現undefined reference，於是我就亂試了

portupgrade -f mysql-client

沒想到之後就可以順利的把 php-mysql、php-mysqli 等 port 順利的編起來了，因為我 Google 了一下都沒有找到相關的解法，所以還是貼出來，希望能讓有需要的人搜尋到提供點幫助 ;-)