[tefmocheck] Mark boot test incorrect failures as infra failures

These failure modes are common sources of false rejections and are likely
infra issues, so mark them as infra failures to indicate to users that
they are likely to be false rejections.

NO_IFTTT=not actually changing the important strings

Bug: 42085023
Change-Id: Icd2200d98425f816f8581e07ef8b7ea6a3ce0299
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1235467
Commit-Queue: Oliver Newman <[email protected]>
Reviewed-by: Ina Huh <[email protected]>

Author: orn688

tools/testing/tefmocheck/string_in_log_check.go

@@ -524,26 +524,30 @@ func fuchsiaLogChecks() []FailureModeCheck {
 			&stringInLogCheck{String: "double fault, halting", Type: lt},
 			// This string can show up in some boot tests.
 			&stringInLogCheck{String: "entering panic shell loop", Type: lt, ExceptStrings: []string{"Boot-test-successful!"}},
-			// For https://fxbug.dev/42067738. These should track all boot test failures
+			// For https://fxbug.dev/42085023. These should track all boot test failures
 			// where either the success string shows up in one of the logs but we fail
 			// to read it, or the test times out before the success string gets written.
-			// LINT.IfChange(seriallistener_timed_out)
 			&stringInLogCheck{
-				String:             "Boot-test-successful!",
-				Type:               lt,
+				String: "Boot-test-successful!",
+				Type:   lt,
+				// This failure mode is likely to be infra-related.
+				InfraFailure:       true,
 				SkipAllPassedTests: true,
 				AlwaysFlake:        true,
 				ExceptBlocks: []*logBlock{
+					// LINT.IfChange(seriallistener_timed_out)
 					{startString: "seriallistener FATAL: timed out before success string", endString: "was read from serial"},
+					// LINT.ThenChange(/tools/testing/seriallistener/cmd/main.go:timed_out)
 				},
 			},
 			&stringInLogCheck{
-				String:             "seriallistener FATAL: timed out before success string",
+				// LINT.IfChange(seriallistener_timed_out)
+				String: "seriallistener FATAL: timed out before success string",
+				// LINT.ThenChange(/tools/testing/seriallistener/cmd/main.go:timed_out)
 				Type:               lt,
 				SkipAllPassedTests: true,
 				AlwaysFlake:        true,
 			},
-			// LINT.ThenChange(/tools/testing/seriallistener/cmd/main.go:timed_out)
 		}...)
 	}