The test failed on branch=release-21.1, cloud=gce:
test artifacts and logs in: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/artifacts/replicagc-changed-peers/restart=false/run_1
	replicagc.go:175,replicagc.go:81,replicagc.go:30,test_runner.go:728: replica count on n1 didn't drop to zero: 97

	cluster.go:1667,context.go:89,cluster.go:1656,test_runner.go:809: dead node detection: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/bin/roachprod monitor teamcity-3125324-1624860626-37-n6cpu4 --oneshot --ignore-empty-nodes: exit status 1 3: dead
		5: 11319
		6: 11891
		4: 11448
		2: 11434
		1: 12247
		Error: UNCLASSIFIED_PROBLEM: 3: dead
		(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:1147
		  | main.wrap.func1
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachprod/main.go:271
		  | github.com/spf13/cobra.(*Command).execute
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:830
		  | github.com/spf13/cobra.(*Command).ExecuteC
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:914
		  | github.com/spf13/cobra.(*Command).Execute
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/vendor/github.com/spf13/cobra/command.go:864
		  | main.main
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachprod/main.go:1889
		  | runtime.main
		  | 	/usr/local/go/src/runtime/proc.go:225
		  | runtime.goexit
		  | 	/usr/local/go/src/runtime/asm_amd64.s:1371
		Wraps: (3) 3: dead
		Error types: (1) errors.Unclassified (2) *withstack.withStack (3) *errutil.leafError