Docker: Disable merged channel access for Windows

This is not supported and anything related to accessing
merged channels on Windows fails due to the need of
using wsl or a named pipe.
On the downside this may crash QC in cases where e.g.
Qt detection still tries to handle qmake as if running
locally, but at the current state this seems to no more
happen automatically (e.g. when using the auto detection).

Change-Id: I983cad66c1210de38a33e26958857a5dcaeef767
Reviewed-by: hjk <hjk@qt.io>

src/plugins/docker/dockerdevice.cpp

@@ -715,6 +715,14 @@ void DockerDevicePrivate::tryCreateLocalFileAccess()
                 .arg(m_container, m_mergedDir)
                     + '\n' + tr("Output: '%1'").arg(out)
                     + '\n' + tr("Error: '%1'").arg(proc.stdErr()));
+        if (HostOsInfo::isWindowsHost()) { // TODO investigate how to make it possible nevertheless
+            m_mergedDir.clear();
+            MessageManager::writeSilently(
+                        tr("Disabling merged channel access. This is not supported and anything "
+                           "related to accessing merged channels on Windows fails due to the need "
+                           "of using wsl or a named pipe."));
+            return;
+        }
     }
 
     m_mergedDirWatcher.addPath(m_mergedDir);