Please note the --enable-mysqlnd, present into build() function.
I'm forced to use it, or else the mysqli related functions are not available into 
phpinfo(). I obtain the same results, if I force to "yes" the PHP_MYSQLND_ENABLED 
variable:

PHP_MYSQLND_ENABLED=yes
export PHP_MYSQLND_ENABLED

There seem to be multiple build targets in your script. Please, paste the one into a bug system comment that leads to the error. Thanks.

No feedback was provided. The bug is being suspended because
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change the status of the bug back to "Open". Thank you.

Here it is the new %build section I use for PHP 5.5.7:
http://pastie.org/private/ufwgue8ipdpfko4aejv0g

I have issues when I start the php-fpm service:
[root@apollo ~]# service php-fpm start
Starting php-fpm: [16-Dec-2013 00:34:58] NOTICE: PHP message: PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/mysql.so' - /usr/lib64/php/modules/mysql.so: undefined symbol: _mysqlnd_fetch_lengths in Unknown on line 0
[16-Dec-2013 00:34:58] NOTICE: PHP message: PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/mysqli.so' - /usr/lib64/php/modules/mysqli.so: undefined symbol: mysqlnd_get_client_version in Unknown on line 0
                                                           [  OK  ]

I forgot to mention that the build is made on CentOS 6.5 x86_64.

/usr/bin/mysql_config:
http://pastie.org/private/umb81fprsj8w2hsyivytzg

I found the issue, is related to the loading order of mysql modules.
If you load mysql.so or mysqli.so before mysqlnd.so, you will get this error. The solution is to rename the modules, so they are loaded into correct order, i.e.:
mysql.so > mysqlnd_mysql.so
mysqli.so > mysqlnd_mysqli.so
pdo_mysql.so > pdo_mysqlnd.so

Then, PHP will load the modules into proper order:
mysqlnd.so
mysqlnd_mysql.so
mysqlnd_mysqli.so
pdo_mysqlnd.so

This is an ugly workaround, the proper solution is when you --enable-mysqlnd, the modules should be automatically renamed at build time for sanity reasons. Further more, we could define a specific loading order, something like:
...
50_mysqlnd.so
60_mysql.so
70_mysqli.so
80_pdo_mysqlnd.so
...

The PHP developer team is more in measure to define the proper PHP module loading order. Looking forward to hear your comments on that matter.

I have the same issue with Fedora 23 and PHP 7.0.1

PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/mysql.so' - /usr/lib64/php/modules/mysql.so: undefined symbol: mysqlnd_connect in Unknown on line 0
PHP 7.0.1 (cli) (built: Dec 16 2015 14:54:25) ( NTS )
Copyright (c) 1997-2015 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2015 Zend Technologies

I've tryid renaming like this:

mysql.so > mysqlnd_mysql.so
mysqli.so > mysqlnd_mysqli.so
pdo_mysql.so > pdo_mysqlnd.so

but the problem continues.