colcon test errors

edit

After installing ROS 2 Crystal from debian packages on Ubuntu 18.04, I followed the colcon tutorial to build and test the sample ros2 packages.

I first created the ros2 workspace:

$ mkdir -p ~/ros2_ws/src
$ cd ~/ros2_ws
$ wget https://raw.githubusercontent.com/ros2/ros2/master/ros2.repos
$ vcs import ~/ros2_ws/src < ros2.repos

I then was able to build the packages successfully:

$ colcon build --symlink-install
Summary: 228 packages finished [1min 3s]

Despite the packages being built successfully, colcon test produces errors.

$ colcon test
Summary: 228 packages finished [28min 27s]
8 packages had stderr output: demo_nodes_cpp osrf_pycommon pendulum_control rcl rclcpp_action rqt test_cli tf2_ros
6 packages had test failures: demo_nodes_cpp pendulum_control rcl rclcpp_action test_cli tf2_ros

Running colcon test again produced different errors.

$ colcon test
Summary: 228 packages finished [27min 22s]
  11 packages had stderr output: composition demo_nodes_cpp image_tools osrf_pycommon pendulum_control rcl rclcpp_action rqt test_communication test_rclcpp tf2_ros
9 packages had test failures: composition demo_nodes_cpp image_tools pendulum_control rcl rclcpp_action test_communication test_rclcpp tf2_ros

I'm not sure what the issue could be, any insight would be really appreciated.

Edit: Adding errors produced by both colcon test attempts. Below are the snippets of the terminal outputs that are relevant to stderr outputs, or test failure outputs:

user@user-machine:~$ cd ros2_ws/
user@user-machine:~/ros2_ws$ colcon test

Starting >>> test_osrf_testing_tools_cpp
--- stderr: osrf_pycommon
test_remove_ansi_escape_senquences (tests.unit.test_terminal_color.test_ansi_re.TestTerminalColorAnsiRe) ... ok
test_remove_ansi_escape_senquences_false_positives (tests.unit.test_terminal_color.test_ansi_re.TestTerminalColorAnsiRe) ... ok
test_split_by_ansi_escape_sequence (tests.unit.test_terminal_color.test_ansi_re.TestTerminalColorAnsiRe) ... ok
test_ansi (tests.unit.test_terminal_color.test_impl.TestTerminalColorImpl) ... ok
test_enable_and_disable_ansi_color_substitution_globally (tests.unit.test_terminal_color.test_impl.TestTerminalColorImpl) ... ok
test_format_color (tests.unit.test_terminal_color.test_impl.TestTerminalColorImpl) ... ok
test_get_ansi_dict (tests.unit.test_terminal_color.test_impl.TestTerminalColorImpl) ... ok
test_sanitize (tests.unit.test_terminal_color.test_impl.TestTerminalColorImpl) ... ok
test_call_prepare_arguments (tests.unit.test_cli_utils.test_verb_pattern.TestCliUtilsVerbPattern) ... /home/user/ros2_ws/build/osrf_pycommon/osrf_pycommon/cli_utils/verb_pattern.py:44: DeprecationWarning: inspect.getargspec() is deprecated, use inspect.signature() or inspect.getfullargspec()
  arguments, _, _, defaults = inspect.getargspec(func)
/home/user/ros2_ws/src/osrf/osrf_pycommon/tests/unit/test_cli_utils/test_verb_pattern.py:69: DeprecationWarning: Please use assertRaisesRegex instead.
  with self.assertRaisesRegexp(ValueError, 'one or two parameters'):
/home/user/ros2_ws/build/osrf_pycommon/osrf_pycommon/cli_utils/verb_pattern.py:55: DeprecationWarning: inspect.getargspec() is deprecated, use inspect.signature() or inspect.getfullargspec()
  ', '.join(inspect.getargspec(func)[0])))
ok
test_split_arguments_by_verb (tests.unit.test_cli_utils.test_verb_pattern.TestCliUtilsVerbPattern) ... ok
test_is_tty (tests.unit.test_terminal_utils.TestTerminalUtils) ... ok
test_async_execute_process_no_emulation_shell_false (tests.unit.test_process_utils.test_async_execute_process.TestProcessUtilsAsyncExecuteProcess) ... /usr/lib/python3.6/asyncio/base_subprocess.py:131: ResourceWarning: unclosed transport <_UnixSubprocessTransport pid=1601 returncode=0 stdin=<_UnixWritePipeTransport closed fd=7 closed> stdout=<_UnixReadPipeTransport closed fd=8 closed> stderr=<_UnixReadPipeTransport closed fd=10 closed>>
  source=self)
ok
test_async_execute_process_no_emulation_shell_false_combined (tests.unit.test_process_utils.test_async_execute_process.TestProcessUtilsAsyncExecuteProcess) ... /usr/lib/python3.6/asyncio/base_subprocess.py:131: ResourceWarning: unclosed transport <_UnixSubprocessTransport pid=1610 returncode=0 stdin=<_UnixWritePipeTransport closed fd=7 closed> stdout=<_UnixReadPipeTransport closed fd=8 closed>>
  source=self)
ok
test_async_execute_process_no_emulation_shell_true (tests.unit.test_process_utils.test_async_execute_process.TestProcessUtilsAsyncExecuteProcess) ... /usr/lib/python3.6/asyncio/base_subprocess.py:131: ResourceWarning: unclosed transport <_UnixSubprocessTransport pid=1611 returncode=0 stdin=<_UnixWritePipeTransport closed fd=7 closed> stdout=<_UnixReadPipeTransport closed fd=8 closed> stderr=<_UnixReadPipeTransport closed fd=10 closed>>
  source=self)
ok
test_async_execute_process_no_emulation_shell_true_combined (tests.unit.test_process_utils.test_async_execute_process.TestProcessUtilsAsyncExecuteProcess) ... /usr/lib/python3 ...