worker: add a SIGCHLD handler to collect worker immediately
As planned by previous patches, add a SIGCHLD handler to get notifications
about worker exits, and deals with worker failure immediately.
Note that the SIGCHLD handler gets unregistered before killworkers(), so
SIGCHLD won't interrupt "killworkers" - making it harder to send kill
signals to waited processes.
#!/bin/sh
# This scripts is used to install dependencies for
# testing Mercurial. Mainly used by Vagrant (see
# Vagrantfile for details).
export DEBIAN_FRONTEND=noninteractive
apt-get update
apt-get install -y -q python-dev unzip
# run-tests.sh is added by Vagrantfile
chmod +x run-tests.sh