Bug #775
closedUST cannot register to any sessiond without HOME env variable
0%
Description
It seems that if the HOME environment variable is not present, an application instrumented with UST cannot register to the sessiond (as root and as user).
With LTTng 2.4 and UST 2.4 (stable release packages).
Here are the 3 lines that appear when starting the program :
libust[27940/27940]: Warning: HOME environment variable not set. Disabling LTTng-UST per-user tracing. (in setup_local_apps() at lttng-ust-comm.c:305)
libust[27940/27941]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:886)
libust[27940/27941]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:886)
This issue was detected with QEMU compiled with UST and libvirt starting the VMs.
When starting qemu manually everything is fine, but when libvirt starts it, it fails.
Libvirt specifies explicitely the environment for the command :
LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin QEMU_AUDIO_DRV=none /usr/bin/qemu-system-x86_64 ..lots-of-other-args...