The test failed on branch=master, cloud=gce:
test artifacts and logs in: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/artifacts/schemachange/during/tpcc/run_1
	monitor.go:128,tpcc.go:279,schemachange.go:429,test_runner.go:777: monitor failure: unexpected node event: 2: dead (exit status 137)
		(1) attached stack trace
		  -- stack trace:
		  | main.(*monitorImpl).WaitE
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/monitor.go:116
		  | main.(*monitorImpl).Wait
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/monitor.go:124
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.runTPCC
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/tpcc.go:279
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.makeSchemaChangeDuringTPCC.func1
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/schemachange.go:429
		  | main.(*testRunner).runTest.func2
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/test_runner.go:777
		  | runtime.goexit
		  | 	/usr/local/go/src/runtime/asm_amd64.s:1371
		Wraps: (2) monitor failure
		Wraps: (3) unexpected node event: 2: dead (exit status 137)
		Error types: (1) *withstack.withStack (2) *errutil.withPrefix (3) *errors.errorString

	cluster.go:1249,context.go:89,cluster.go:1237,test_runner.go:866: dead node detection: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/bin/roachprod monitor teamcity-3317393-1629267491-66-n5cpu16 --oneshot --ignore-empty-nodes: exit status 1 5: skipped
		2: dead (exit status 137)
		4: 11681
		1: 12120
		3: 11716
		Error: UNCLASSIFIED_PROBLEM: 2: dead (exit status 137)
		(1) UNCLASSIFIED_PROBLEM
		Wraps: (2) attached stack trace
		  -- stack trace:
		  | main.glob..func14
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachprod/main.go:1173
		  | main.wrap.func1
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachprod/main.go:281
		  | github.com/spf13/cobra.(*Command).execute
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:856
		  | github.com/spf13/cobra.(*Command).ExecuteC
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:960
		  | github.com/spf13/cobra.(*Command).Execute
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:897
		  | main.main
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachprod/main.go:2107
		  | runtime.main
		  | 	/usr/local/go/src/runtime/proc.go:225
		  | runtime.goexit
		  | 	/usr/local/go/src/runtime/asm_amd64.s:1371
		Wraps: (3) 2: dead (exit status 137)
		Error types: (1) errors.Unclassified (2) *withstack.withStack (3) *errutil.leafError