make error "undefined reference to `sd_bus_match_signal_async'" on Ubuntu

[anttikyl]

I get the following error on Ubuntu 16.04. Tried with two different machines and running into the same issue on both.

make[2]: Entering directory '/home/antti.kyllonen/work/crun'
  CC       src/libcrun/libcrun_la-utils.lo
  CC       src/libcrun/libcrun_la-cloned_binary.lo
  CC       src/libcrun/libcrun_la-container.lo
  CC       src/libcrun/libcrun_la-cgroup.lo
src/libcrun/cgroup.c: In function 'systemd_check_job_status_setup':
src/libcrun/cgroup.c:756:9: warning: implicit declaration of function 'sd_bus_match_signal_async' [-Wimplicit-function-declaration]
   ret = sd_bus_match_signal_async (bus,
         ^
  CC       src/libcrun/libcrun_la-criu.lo
  CC       src/libcrun/libcrun_la-linux.lo
  CC       src/libcrun/libcrun_la-seccomp.lo
  CC       src/libcrun/libcrun_la-ebpf.lo
  CC       src/libcrun/libcrun_la-error.lo
  CC       src/libcrun/libcrun_la-status.lo
  CC       src/libcrun/libcrun_la-terminal.lo
  CC       src/libcrun/libcrun_la-chroot_realpath.lo
  CC       src/libcrun/libcrun_la-signals.lo
  CCLD     libcrun.la
ar: `u' modifier ignored since `D' is the default (see `U')
  CC       src/crun-crun.o
  CC       src/crun-run.o
  CC       src/crun-delete.o
  CC       src/crun-kill.o
  CC       src/crun-pause.o
  CC       src/crun-unpause.o
  CC       src/crun-spec.o
  CC       src/crun-exec.o
  CC       src/crun-list.o
  CC       src/crun-create.o
  CC       src/crun-start.o
  CC       src/crun-state.o
  CC       src/crun-update.o
  CC       src/crun-ps.o
  CC       src/crun-checkpoint.o
  CC       src/crun-restore.o
  CCLD     crun
./.libs/libcrun.a(libcrun_la-cgroup.o): In function `systemd_check_job_status_setup':
/home/antti.kyllonen/work/crun/src/libcrun/cgroup.c:756: undefined reference to `sd_bus_match_signal_async'
collect2: error: ld returned 1 exit status
Makefile:1012: recipe for target 'crun' failed
make[2]: *** [crun] Error 1
make[2]: Leaving directory '/home/antti.kyllonen/work/crun'
Makefile:1519: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/antti.kyllonen/work/crun'
Makefile:743: recipe for target 'all' failed
make: *** [all] Error 2

[giuseppe]

looks like the systemd version is too old and that function doesn't exist. Any chance to update to a newer systemd?
In alternative you could try to build without systemd support, but then you are forced to use cgroupfs to manage cgroups

[anttikyl]

Sorry for the late reply. I've built without systemd support and it works fine for my use.

However, it's worth noting that Ubuntu uses systemd v229, but sd_bus_match_signal_async wasn't added until v237.