Block ActivateBestChain to empty validationinterface queue

src/test/test_bitcoin.cpp

@@ -69,9 +69,9 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
         fs::create_directories(pathTemp);
         gArgs.ForceSetArg("-datadir", pathTemp.string());
 
-        // Note that because we don't bother running a scheduler thread here,
-        // callbacks via CValidationInterface are unreliable, but that's OK,
-        // our unit tests aren't testing multiple parts of the code at once.
+        // We have to run a scheduler thread to prevent ActivateBestChain
+        // from blocking due to queue overrun.
+        threadGroup.create_thread(boost::bind(&CScheduler::serviceQueue, &scheduler));
         GetMainSignals().RegisterBackgroundSignalScheduler(scheduler);
 
         mempool.setSanityCheck(1.0);