It seems that our PHP_ADD_EXTENSION_DEP() macro from acinclude.m4 does not actually do any
linking against the dependent extension despite the comment in it:
dnl Some systems require that we link $2 to $1 when building
The consequence of this is that if the dependent extension (like igbinary.so) is not
loaded and you try to load your depending extension (like my memcached.so), you'll get an
php: symbol lookup error: /usr/local/lib/php/20060613-debug/memcached.so: undefined
I asked Wez and he said that the only way to fix it is to do the actual linking which is
what he proposed a while back. Any reason why it hasn't been done?