gearman-server broken on Debian 9

Problem: On Debian 9, gearman-server does not start. "gearadmin" also exposes some errors: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=918729

$ apt show gearman-server
Package: gearman-server
Version: 1.130.1-1

Manual start:

$ start-stop-daemon --start --quiet --pidfile /var/run/gearmand.pid --exec /usr/bin/gearmand -- --pidfile=/var/run/gearmand.pid --debug=1

When a worker tries to connect:

Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Gearman/Server/Client.pm line 551.
Error: Can't locate object method "CMD_" via package "Gearman::Server::Client" at /usr/share/perl5/Gearman/Server/Client.pm line 552.

$ ./bin/phinde-worker.php
PHP Warning:  GearmanWorker::work(): gearman_worker_grab_job(GEARMAN_UNEXPECTED_PACKET) unexpected packet:ERROR -> libgearman/worker.cc:794 in phinde-worker.php on line 36

Solution: use gearman-job-server (C-reimplementation) instead of gearman-server.