The test failed on branch=master, cloud=gce:
test artifacts and logs in: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/artifacts/decommission/mixed-versions/run_1
	cluster.go:1944,mixed_version_decommission.go:115,versionupgrade.go:213,mixed_version_decommission.go:97,decommission.go:83,test_runner.go:777: output in run_073307.406798236_n3_v2120beta2cockroach_node_decommission: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/bin/roachprod run teamcity-3674519-1635924358-09-n4cpu4:3 -- ./v21.2.0-beta.2/cockroach node decommission --wait=none --insecure 1 returned: exit status 20
		(1) attached stack trace
		  -- stack trace:
		  | main.(*clusterImpl).RunE
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/cluster.go:2034
		  | main.(*clusterImpl).Run
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/cluster.go:1942
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.partialDecommissionStep.func1
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/mixed_version_decommission.go:115
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.(*versionUpgradeTest).run
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/versionupgrade.go:213
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.runDecommissionMixedVersions
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/mixed_version_decommission.go:97
		  | github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests.registerDecommission.func4
		  | 	/home/agent/work/.go/src/github.com/cockroachdb/cockroach/pkg/cmd/roachtest/tests/decommission.go:83
		  | 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) output in run_073307.406798236_n3_v2120beta2cockroach_node_decommission
		Wraps: (3) /home/agent/work/.go/src/github.com/cockroachdb/cockroach/bin/roachprod run teamcity-3674519-1635924358-09-n4cpu4:3 -- ./v21.2.0-beta.2/cockroach node decommission --wait=none --insecure 1 returned
		  | stderr:
		  | ERROR: failed to connect to the node: initial connection heartbeat failed: rpc error: code = Unknown desc = version compatibility check failed on ping request: cluster requires at least version 21.2-4, but peer has version 21.1-1164
		  | Failed running "node decommission"
		  | Error: COMMAND_PROBLEM: exit status 1
		  | (1) COMMAND_PROBLEM
		  | Wraps: (2) Node 3. Command with error:
		  |   | ``````
		  |   | ./v21.2.0-beta.2/cockroach node decommission --wait=none --insecure 1
		  |   | ``````
		  | Wraps: (3) exit status 1
		  | Error types: (1) errors.Cmd (2) *hintdetail.withDetail (3) *exec.ExitError
		  |
		  | stdout:
		Wraps: (4) exit status 20
		Error types: (1) *withstack.withStack (2) *errutil.withPrefix (3) *cluster.WithCommandDetails (4) *exec.ExitError