Merge pull request #8037 from adelez/known_failures

Escapt +

tools/run_tests/run_build_statistics.py

@@ -64,7 +64,7 @@ _KNOWN_ERRORS = [
     'Failed to build workspace Tests with scheme AllTests',
     'Build timed out',
     'FATAL: Unable to produce a script file',
-    'FAILED: build_docker_c++',
+    'FAILED: build_docker_c\+\+',
     'cannot find package \"cloud.google.com/go/compute/metadata\"',
     'LLVM ERROR: IO failure on output stream.',
     'MSBUILD : error MSB1009: Project file does not exist.',
@@ -72,6 +72,7 @@ _KNOWN_ERRORS = [
     'Failed to fetch from http://github.com/grpc/grpc.git',
     ('hudson.remoting.RemotingSystemException: java.io.IOException: '
      'Backing channel is disconnected.'),
+    'hudson.remoting.ChannelClosedException',
     'FAILED: bins/tsan/qps_openloop_test GRPC_POLL_STRATEGY=epoll',
     'FAILED: bins/tsan/qps_openloop_test GRPC_POLL_STRATEGY=legacy',
     'FAILED: bins/tsan/qps_openloop_test GRPC_POLL_STRATEGY=poll',