Comment 6 for bug 1401364

It's a (cunningly hidden) leak in ClientLibrary.surface_create.

Cunningly hidden in that it only manifests after a call to fork(), and only in the child.
So most people running the testsuite at home won't notice, because we run each test
in a separate process by default.

CI runs everything in one process, so hits this.

To duplicate that environment, you need to run the tests in a build with
cmake -DDISABLE_GTEST_TEST_DISCOVERY=ON -DENABLE_MEMCHECK_OPTION=ON