Qt Creator misconfigures itself on first run if qt4-qmake is installed (does not respect qt5-default)

Qt Creator only auto-detects Qt 4 and not Qt 5, if both are installed. If qt4-qmake is then removed, Qt 5 will be automatically detected, although only if the old Qt Creator configuration is first removed.

If you are having this bug, multiple things in Qt Creator configuration may be broken. You can either try to fix the problems manually, or remove the qt4-qmake package and reset the Qt Creator configuration. See below for instructions on both.

== Similar misconfiguration causes ==

The following cases cause some of the same problems, even though they are not related to having qt4-qmake installed:

- Qt Creator may misconfigure itself if a proper removal of the old Qt 5 Beta 1 PPA has not been done: http://askubuntu.com/questions/254800/how-can-i-update-the-ubuntu-sdk-preview-from-the-qt-5-beta-ppa-to-the-qt-5-relea
- Qt Creator may misconfigure itself if not all of ubuntu-sdk has been installed before the first launch. Either the Qt Creator configuration resetting or manual fixing is needed also in case of functionality problems encountered.

== Symptoms ==

Symptoms of having the problem include:
- Not being able to "Run" QML projects
- Getting QML Import complaints when going to the Design tab after opening a .qml file first in the editor
- Missing Ubuntu UI wizard options (this can also be cause by not having the special package ubuntu-qtcreator-plugins from ubuntu-sdk-ppa installed)

== Methods of fixing ==

=== Automatically fixing Qt Creator settings by resetting configuration ===

If you can or want to reset all the Qt Creator configuration:
1. Quit Qt Creator
2. Remove the configuration files: rm -r .config/Trolltech.conf .config/Qt* .config/Nokia*
3. Remove the qt4-qmake package if you didn't already remove it: sudo apt-get remove --purge qt4-qmake
4. Check that ubuntu-sdk is installed: sudo apt-get install ubuntu-sdk
5. Now start Qt Creator, and it should have everything functional.

=== Manually fixing Qt Creator settings ===

You can go through the manual route if you don't want to remove all your Qt Creator settings, or just want to learn about how to configure Qt Creator in general.

As a first step you need to go Tools -> Options -> Qt Versions -> Add... and add the /usr/bin/qmake which then identifies itself as Qt 5.0.0 or 5.0.1. Remove Qt 4 references if you don't need those.

If still having problems, you need to check the Kits tab as well to double-check that the "Desktop (default)" has Qt version "Qt 5.0.1 (System)" set. Not having it set can for example result in Build -> Run being greyed out when having qmlproject like lp:~dpm/+junk/ubuntu-app-dev-cookbook opened.

If the Build -> Run is still greyed out after this when you've a CurrencyConverter.qmlproject open from above link, but Tools -> Options settings seem fine, open the "Projects" from the left pane in Qt Creator. Check that you have a kit defined (use the "Add Kit" dropdown if not), after which you should have the Desktop -> Run tab filled with "Run configuration: "QML Scene" for example. Now the Run should work.

Also the QML Import Path might be broken if qt4-qmake package was installed during the time of first run of Qt Creator. This is shown in the Design tab from the left pane not functioning for Ubuntu UI projects.

TODO: how to reset the QML Import Path from the UI without resetting all configuration?