i was recently trying to install the event module for php, and ran into a weird error:
$ pecl install event ... configure: error: bufferevent_openssl_get_ssl not found in event_openssl library, or the library is not installed
after scratching my head for a while, i found out this was because i compiled libevent2 *before* installing openssl-devel. the error went away after a
make clean && make && make install for libevent2.