runtime/vm/os_thread.cc: 348: error: Could not start thread DartWorker #164591
Description
Soon after #164554, we've hit some postsubmit failures that I haven't seen before:
26:42 +6876 ~120 -1: loading /b/s/w/ir/x/w/flutter sdk/packages/flutter/test/semantics/semantics_binding_test.dart [E]
Failed to load "/b/s/w/ir/x/w/flutter sdk/packages/flutter/test/semantics/semantics_binding_test.dart":
Unexpected character (at character 1)
../../runtime/vm/os_thread.cc: 348: error: Could not start thread DartWorke...
^