Description:
------------
Using a custom prefix for the libevent installation (/usr/local/libevent-1.4.13) doesn't get picked up by the configure script, even though I properly used the --with-libevent-dir option. Unless the prefix for the libevent installation is a path that ldconfig knows about, the configure fails.

I could "fix" it with:

export LD_LIBRARY_PATH=/usr/local/libevent-$libevent_version/lib

within my build script which gives me the idea that the configure fails to properly set its environment. Still an arcane method though.

Test script:
---------------
./configure [...] --enable-fpm --with-fpm-user=php-fpm --with-fpm-group=php-fpm --with-libevent-dir=/usr/local/libevent-1.4.13

Expected result:
----------------
To run configure without errors.

Actual result:
--------------
./configure says:

checking for FPM build... yes
checking for libevent >= 1.4.11 install prefix... /usr/local/libevent-1.4.13
no
configure: error: build test failed. Please check the config.log for details.

config.log says:

configure:9409: checking for libevent >= 1.4.11 install prefix
configure:9524: gcc -o conftest -g -O2 -fvisibility=hidden  -I/usr/local/libevent-1.4.13/include  -L/usr/local/libevent-1.4.13/lib conftest.c  -levent 1>&5
configure:9724: gcc -o conftest -g -O2 -fvisibility=hidden   conftest.c -L/usr/local/libevent-1.4.13/lib -levent  1>&5
configure: failed program was:
#line 9713 "configure"
#include "confdefs.h"

    
    char event_init();
    int main() {
      event_init();
      return 0;
    }