tests: ensure strace is available in the docker image..

..and enable privileged=True since that's needed for ptrace()

tests/build_docker_image.py

@@ -40,6 +40,8 @@ RUN echo "export VISIBLE=now" >> /etc/profile
 
 EXPOSE 22
 CMD ["/usr/sbin/sshd", "-D"]
+
+RUN apt-get install -y strace && apt-get clean && { echo '#!/bin/bash\nexec strace -ff -o /tmp/pywrap$$.trace python2.7 "$@"' > /usr/local/bin/pywrap; chmod +x /usr/local/bin/pywrap; }
 """
 
 

tests/testlib.py

@@ -134,6 +134,7 @@ class DockerizedSshDaemon(object):
         self.container = self.docker.containers.run(
             image='d2mw/mitogen-test',
             detach=True,
+            privileged=True,
             publish_all_ports=True,
         )
         self.container.reload()