Utils: Send start failed if no ProcessInterface

Change-Id: I38cdce9812bcec3240e3fb4f30a1dd266a5515e9
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/utils/process.cpp

@@ -1251,7 +1251,19 @@ void Process::start()
     } else {
         processImpl = d->createProcessInterface();
     }
-    QTC_ASSERT(processImpl, return);
+
+    if (!processImpl) {
+        // This happens if a device does not implement the createProcessInterface() function.
+        d->m_result = ProcessResult::StartFailed;
+        d->m_resultData.m_exitCode = 255;
+        d->m_resultData.m_exitStatus = QProcess::CrashExit;
+        d->m_resultData.m_errorString = Tr::tr("Failed to create process interface for \"%1\"")
+                                            .arg(d->m_setup.m_commandLine.toUserOutput());
+        d->m_resultData.m_error = QProcess::FailedToStart;
+        d->emitGuardedSignal(&Process::done);
+        return;
+    }
+
     d->setProcessInterface(processImpl);
     d->m_state = QProcess::Starting;
     d->m_process->m_setup = d->m_setup;

src/plugins/projectexplorer/devicesupport/idevice.cpp

@@ -290,7 +290,6 @@ FilePath IDevice::searchExecutable(const QString &fileName, const FilePaths &dir
 
 ProcessInterface *IDevice::createProcessInterface() const
 {
-    QTC_CHECK(false);
     return nullptr;
 }