requires: re-use vfs.tryread for simplicity
Avoids calling `set` twice or having to re-raise an exception and implements the routine with a single return expression.
#!/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