I am having the same issue on Ubuntu 14.04.
The problem seems to be that pgbouncer asks libssl (via libusual) to load a non
existing file "/etc/ssl/cert.pem".
The configuration script for libusual tries to autodetect the CA file as either
/etc/ssl/certs/ca-certificates.crt
/etc/ssl/cert.pem
The first file does exist, the latter does not. So it seems that build-time
configuration for pgbouncer/libusual is not correct here.
As a workaround, I created a symlink:
/etc/ssl/cert.pem -> /etc/ssl/certs/ca-certificates.crt
Greetings,
Christian
