Fix CI fails

backend/ethereum/channel/conclude_test.go

@@ -102,10 +102,13 @@ func TestAdjudicator_ConcludeWithSubChannels(t *testing.T) {
 	// 0. setup
 
 	const (
-		numParts               = 2
-		maxCountSubChannels    = 3
-		maxCountSubSubChannels = 3
-		maxChallengeDuration   = 3600
+		numParts                  = 2
+		maxCountSubChannels       = 3
+		maxCountSubSubChannels    = 3
+		minFundingTXBlocksTimeout = 200
+		minChallengeDuration      = minFundingTXBlocksTimeout
+		maxChallengeDuration      = 3600
+		challengeDurationSpread   = maxChallengeDuration - minChallengeDuration
 	)
 	ctx, cancel := newDefaultTestContext()
 	defer cancel()
@@ -121,7 +124,7 @@ func TestAdjudicator_ConcludeWithSubChannels(t *testing.T) {
 		accounts          = s.Accs
 		participants      = s.Parts
 		asset             = s.Asset
-		challengeDuration = uint64(rng.Intn(maxChallengeDuration))
+		challengeDuration = uint64(rng.Intn(challengeDurationSpread) + minChallengeDuration)
 		makeRandomChannel = func(rng *rand.Rand, ledger bool) paramsAndState {
 			return makeRandomChannel(rng, participants, asset, challengeDuration, ledger)
 		}

backend/ethereum/channel/test/simulated.go

@@ -52,11 +52,12 @@ type SimulatedBackend struct {
 	backends.SimulatedBackend
 	sbMtx sync.Mutex // protects SimulatedBackend
 
-	faucetKey  *ecdsa.PrivateKey
-	faucetAddr common.Address
-	clockMu    sync.Mutex    // Mutex for clock adjustments. Locked by SimTimeouts.
-	mining     chan struct{} // Used for auto-mining blocks.
-	commitTx   bool          // Whether each transaction is committed.
+	faucetKey     *ecdsa.PrivateKey
+	faucetAddr    common.Address
+	clockMu       sync.Mutex    // Mutex for clock adjustments. Locked by SimTimeouts.
+	mining        chan struct{} // Used for auto-mining blocks.
+	stoppedMining chan struct{} // For making sure that mining stopped.
+	commitTx      bool          // Whether each transaction is committed.
 }
 
 type (
@@ -146,9 +147,11 @@ func (s *SimulatedBackend) StartMining(interval time.Duration) {
 	}
 
 	s.mining = make(chan struct{})
+	s.stoppedMining = make(chan struct{})
 	go func() {
 		log.Trace("Started mining")
 		defer log.Trace("Stopped mining")
+		defer close(s.stoppedMining)
 
 		for {
 			s.Commit()
@@ -165,8 +168,10 @@ func (s *SimulatedBackend) StartMining(interval time.Duration) {
 
 // StopMining stops the auto-mining of the simulated blockchain.
 // Must be called exactly once to free resources iff `StartMining` was called.
+// Waits until the auto-mining routine terminates.
 func (s *SimulatedBackend) StopMining() {
 	close(s.mining)
+	<-s.stoppedMining
 }
 
 // Reorg applies a chain reorg.

backend/ethereum/subscription/resistanteventsub.go

@@ -257,8 +257,6 @@ func (s *ResistantEventSub) isFinal(event *Event) bool {
 // Close closes the sub and the underlying `EventSub`.
 // Can be called more than once. Is thread safe.
 func (s *ResistantEventSub) Close() {
-	if err := s.closer.Close(); err != nil && !pkgsync.IsAlreadyClosedError(err) {
-		log.WithError(err).Error("could not close EventSub")
-	}
+	s.closer.Close() // Silently ignore repeated close calls, as it is allowed in this function's specification.
 	// NOTE: The underlying `EventSub` is closed in the `OnCloseAlways` hook.
 }