Improve error handling

CMakeLists.txt

@@ -217,7 +217,6 @@ target_sources(${QUOTIENT_LIB_NAME} PUBLIC FILE_SET HEADERS BASE_DIRS .
         Quotient/jobs/mediathumbnailjob.cpp
         Quotient/jobs/downloadfilejob.cpp
         Quotient/keyverificationsession.cpp
-        Quotient/e2ee/e2ee_common.cpp
         Quotient/keyimport.cpp
         libquotientemojis.qrc
 )

Quotient/connection.cpp

@@ -395,6 +395,12 @@ void Connection::Private::setupCryptoMachine(const QByteArray& picklingKey)
     mxIdForDb.replace(u':', u'_');
     const QString databasePath{ QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) % u'/' % mxIdForDb % u'/' % q->deviceId() };
     cryptoMachine = crypto::init(stringToRust(q->userId()), stringToRust(q->deviceId()), stringToRust(databasePath), bytesToRust(picklingKey));
+    if (!(*cryptoMachine)->is_ok()) {
+        //TODO as part of #782: if crypto machine creation fails, make PendingConnection fail to create a Connection. Then clients can show these errors nicely
+        // and we don't have to guard all functions for the crypto machine not being available.
+        qCritical() << "Failed to load crypto machine" << (int) (*cryptoMachine)->error() << stringFromRust((*cryptoMachine)->error_string());
+        qApp->exit(1);
+    }
 }
 
 void Connection::Private::completeSetup(const QString& mxId, bool newLogin,