[1015/1548] webkitpy.tool.steps.steps_unittest.StepsTest.test_runtests_bindings failed: Traceback (most recent call last): File "/Volumes/Data/slave/ios-simulator-10-release-tests-wk2/build/Tools/Scripts/webkitpy/tool/steps/steps_unittest.py", line 258, in test_runtests_bindings OutputCapture().assert_outputs(self, step.run, [{}], expected_logs=expected_logs) File "/Volumes/Data/slave/ios-simulator-10-release-tests-wk2/build/Tools/Scripts/webkitpy/common/system/outputcapture.py", line 105, in assert_outputs testassert(logs_string, expected_logs) AssertionError: "MOCK run_command: ['perl', 'Tools/Scripts/webkit-build-directory', '--mac'], cw [truncated]... != "MOCK run_and_throw_if_fail: ['Tools/Scripts/run-bindings-tests', '--json-output [truncated]... - MOCK run_command: ['perl', 'Tools/Scripts/webkit-build-directory', '--mac'], cwd=/mock-checkout MOCK run_and_throw_if_fail: ['Tools/Scripts/run-bindings-tests', '--json-output=/tmp/bindings_test_results.json'], cwd=/mock-checkout https://build.webkit.org/builders/Apple%20iOS%2010%20Simulator%20Release%20WK2%20%28Tests%29/builds/4624
<rdar://problem/31093812>
build_directory() in webkitpy/port/config.py runs the webkit-build-directory command. build_path() in webkitpy/port/base.py sometimes calls the above function if it doesn't have it cached. AIUI the order in which the tests are run using webkitpy is non-deterministic, so that might be the source of flakiness here. If that is the case, the best solution would be to just make the webkit-build-directory line optional for the unit tests somehow.
Adding some color to my previous comment: Running webkit-build-directory is done as a reaction to a cache miss inside webkitpy, so it's not strictly an error.
*** This bug has been marked as a duplicate of bug 177751 ***