# A run in a shared test VM dies: "X connection to :2 broken"

## Symptoms

A game running on its own Xvfb display in a VM that other sessions also use dies in the
middle of a run; its log ends with "X connection to :2 broken (explicit kill or server
shutdown)", and the other display's Xvfb has a new process number.

## Cause

Another session's stop script ran a bare `pkill Xvfb`, which ends every Xvfb in the machine
(*observed*: POD's `run/vm/inside.sh stop`, twice in one evening). A related trap, `pkill -f`
matching the ssh command that holds it, is
[its own entry](https://tanepiper.github.io/game-frame/knowhow/vm-ssh-pkill-matches-itself.md).

## What to do

Scripts on a shared machine stop only their own processes: `pkill -f "Xvfb :1"`, not
`pkill Xvfb`.
For a long run, start the X server under a name of its own (a symlink: `~/bin/Xglide`), which
nobody else's `pkill Xvfb` matches. Give each session its own display and Wine prefix.