Merge pull request #224 from iLib-js/updateQTguide

Update qtTest.md file to add information regarding qt install

docs/QtTest.md

@@ -6,12 +6,27 @@ In order to run a test on QT/QML environment, You need to some setting in Advanc
 You need to install [QT](https://www.qt.io/download) on your machine first. We've confirmed that iLib works in QT 5.9.  The latest version of QT is not guaranteed yet. I recommend installing version under `QT 5.9` and `QtQuick 2.5+`
 
 ##### 2. Modify qt/build.properties file
-When you checkout iLib sources, Default values in `qt/build.properties` is  `QTBIN=/opt/qt55/bin` If you install different location, You need to modify this file. 
+When you checkout iLib sources, Default values in `qt/build.properties` is  `QTBIN=/opt/qt55/bin` If you install different locations, You need to modify this file.
+
+##### Additional Information
+If your machine still doesn't point QT where you want, Please modify `default.conf` following way.
+
+[qtchooser](https://www.systutorials.com/docs/linux/man/1-qtchooser/): - a wrapper used to select between Qt development binary versions
+
+a. Check current system status first by qtchooser command
+~~~~~
+> qtchooser –print-env
+~~~~~
+b. Modify `defult.conf`
+It's System-wide configuration file. If a `default.conf` is provided, the settings from it will be automatically used in case nothing else is selected.
+~~~~~
+> sudo vi /usr/lib/x86_64-linux-gnu/qtchooser/default.conf
+~~~~~
 
 ##### 3. Run Qt/QML Test by executing ant
 Executing below command under qt/ directory.
 ~~~~~
-ant test.qt.nodeunit
+> ant test.qt.nodeunit
 ~~~~~
 
 ### Trouble Shooting ###
@@ -24,8 +39,8 @@ ant test.qt.nodeunit
 You might need to install package below:
 
 ~~~~~
- sudo apt-get install libnetpbm10-dev
- sudo apt-get install libglu1-mesa-dev
+ > sudo apt-get install libnetpbm10-dev
+ > sudo apt-get install libglu1-mesa-dev
 ~~~~~
 
 2. When you faced errors as below,