I've just tried to install HAProxy 2.5.4, as provided by the OpenSUSE `servers:http` package; I'm upgrading from HAProxy 2.4.1.
Running `haproxy -c -f /etc/haproxy/haproxy.cfg` fails with exit code 1, but without any other message. (It previously complained about `nbproc 1`, which I've removed.) Adding a `-V`, as in `haproxy -V -c -f /etc/haproxy/haproxy.cfg` additionally complains about `forceclose`, which if removed it seems to solve the issue. There are also some other `[WARNING]` messages that don't appear without `-V`. Perhaps anything above (and including) `[WARNING]` should be the default when checking a configuration file. Thanks, Ciprian.

