kvserver: disable kv.expiration_leases_only.enabled metamorphism un…

…der deadlock

TestClusters are usually so slow under deadlock detection that they're
unable to maintain leases/leadership/liveness, especially with
expiration leases.

Epic: none
Release note: None

pkg/kv/kvserver/replica_range_lease.go

@@ -63,6 +63,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/retry"
 	"github.com/cockroachdb/cockroach/pkg/util/stop"
+	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
 	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
 	"github.com/cockroachdb/cockroach/pkg/util/tracing"
 	"github.com/cockroachdb/errors"
@@ -81,7 +82,11 @@ var ExpirationLeasesOnly = settings.RegisterBoolSetting(
 	settings.SystemOnly,
 	"kv.expiration_leases_only.enabled",
 	"only use expiration-based leases, never epoch-based ones (experimental, affects performance)",
-	util.ConstantWithMetamorphicTestBool("kv.expiration_leases_only.enabled", false),
+	// false by default. Metamorphically enabled in tests, but not in deadlock
+	// builds because TestClusters are usually so slow that they're unable
+	// to maintain leases/leadership/liveness.
+	!syncutil.DeadlockEnabled &&
+		util.ConstantWithMetamorphicTestBool("kv.expiration_leases_only.enabled", false),
 )
 
 var leaseStatusLogLimiter = func() *log.EveryN {