Comment 2 for bug 1341623

StacktraceTop:
 nih_free (ptr=0x0) at alloc.c:318
 cgm_get (controller=0x4272c7 "systemd", cgroup_path=0x8b6ea1 "user/1000.user/c2.session", cgroup_path@entry=0x8b6ea0 "/user/1000.user/c2.session", key=key@entry=0x433f05 "tasks") at ../src/shared/cgmanager.c:143
 cg_enumerate_tasks (controller=0x42618a "name=systemd", path=0x8b6ea0 "/user/1000.user/c2.session", _f=_f@entry=0x7fffff837248) at ../src/shared/cgroup-util.c:128
 cg_is_empty (controller=<optimized out>, path=<optimized out>, ignore_self=true) at ../src/shared/cgroup-util.c:1125
 cg_is_empty_recursive (controller=controller@entry=0x42618a "name=systemd", path=0x8b6ea0 "/user/1000.user/c2.session", ignore_self=ignore_self@entry=true) at ../src/shared/cgroup-util.c:1171