CI test failures "boost thread: trying joining itself: Resource deadlock avoided"

[jacobperron]

Several tests are failing on Foxy CI due to a boost thread error:

https://build.osrfoundation.org/job/ros2_gazebo_pkgs-ci-default_foxy-focal-amd64/22

terminate called after throwing an instance of 'boost::wrapexcept' what(): boost thread: trying joining itself: Resource deadlock avoided

The following tests are failing in the referenced job:

• test_gazebo_ros_joint_effort
• test_gazebo_ros_diff_drive
• test_gazebo_ros_harness

[jacobperron]

Another instance of the same error on Dashing CI: https://build.osrfoundation.org/job/ros2_gazebo11_pkgs-ci-default_dashing-bionic-amd64/6/

The following test failed:

• test_gazebo_ros_properties

[jacobperron]

Again on Foxy CI during test_gazebo_ros_tricycle_drive: https://build.osrfoundation.org/job/ros2_gazebo_pkgs-ci-default_foxy-focal-amd64/23

[scpeters]

I have seen these failures in upstream gazebo tests as well