(Another possibility is that I mean "for Taskcluster xpcshell failures".) https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&revision=7c576fe3279d87543f0a03b844eba7bc215e17f1&selectedJob=5133956 is a simple little xpcshell timeout, but in the autoclassify panel that expands out to LOG ERROR | Timeout exceeded for shell call 'adb shell /data/local/xpcb/xpcw /mnt/sdcard/tests/xpc/dom/indexedDB/test/unit -r /mnt/sdcard/tests/xpc/c/httpd.manifest --greomni /data/local/xpcb/target.apk -m -s -e 'const _HEAD_JS_PATH = "/mnt/sdcard/tests/xpc/head.js";' -e 'const _MOZINFO_JS_PATH = "/mnt/sdcard/tests/xpc/p/mozinfo.json";' -e 'const _TESTING_MODULES_DIR = "/mnt/sdcard/tests/xpc/m";' -f /mnt/sdcard/tests/xpc/head.js -e 'const _SERVER_ADDR = "localhost"' -e 'const _HEAD_FILES = ["/mnt/sdcard/tests/xpc/dom/indexedDB/test/unit/xpcshell-head-parent-process.js"];' -e 'const _TAIL_FILES = ;' -e 'const _JSDEBUGGER_PORT = 0;' -e 'const _TEST_FILE = ["test_quotaExceeded_recovery.js"];' -e 'const _TEST_NAME = "xpcshell.ini:dom/indexedDB/test/unit/test_quotaExceeded_recovery.js"' -e '_execute_test(); quit(0);'; echo $?' and LOG ERROR | xpcshell.ini:dom/indexedDB/test/unit/test_quotaExceeded_recovery.js | Process still running after test! and LOG ERROR | TEST-UNEXPECTED-FAIL | Received SIGINT (control-C), so stopped run. (Use --keep-going to keep running tests after killing one with SIGINT) before we even get to the test that timed out, followed by (in the same place as in the error summary panel, this time) another suggestion to use --keep-going after the line about the timeout. I'm willing to believe that's a bug in structured logs for (Android) xpcshell, but since I don't know what a structured log is supposed to contain or where to find one, I can't very well file against them.
Given the ton of junk in https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&revision=d1fd56faaeb92f9c931e6a85d61b0e22a1ff4373&selectedJob=5134858 probably "multiple bugs with structured logging for xpcshell, some of them Android specific"