Since version 5.14.0 Qt is roamable , i.e. you can move your Qt installation to another directory without breaking functionality or loading plugins.
What does this mean to me?
Let's move on to the role of the Qt Build Master in a Windows project. You are the one who knows all the argument settings by heart. You know which optimization screw to turn and which unnecessary feature to turn off.
Your build of Qt is perfectly tailored to the project, and you provide a zip file containing the Qt installation.
- configure -prefix C:/Qt/5.12.6 ...more options...
- jom
- jom install
- zip -r X:\shared_stuff\qt-5.12.6.zip C:\Qt\5.12.6
Then your teammates extract the archive to the same location and everything works great.
Now, for whatever reason, Joe Developer must unpack the Qt installation into some other drive/directory.
Qt does not work in this other directory. QMake will not work properly. Plugins cannot be loaded. Qt assets not found.
Why is everything broken?
Historically, the Qt configuration has embedded the installation directory in the qmake executable and the Qt5Core library. The logic in QLibraryInfo tries to find plugins, assets, and mkspecs under a hard-coded prefix, which is always what you passed in for configuration with the -prefix argument.
Does moving the installation directory work in Qt 5.14?
Oh yeah! Starting with Qt 5.14.0, the installation prefix can be automatically determined by the location of the Qt5Core library or the executable itself, without using hardcoded paths.
This automatism is controlled at the time Qt is configured via the
move function
.
This feature is enabled by default for non-static builds of Qt.
If you need a relocatable static assembly, enable this feature manually:
- onfigure -static -feature-relocatable ...
The caveat about relocatable static assemblies is that Qt's internal translations are not handled automatically.
You will need to deploy the Qt translation files along with your application.
This difference from a non-relocatable assembly is the reason why
relocation
is disabled by default for static assemblies.
If I don't like it, can I turn this feature off?
Of course you can.
- configure -no-feature-relocatable ...
will return the old behavior.
For example, Linux distributions do not need relocatable Qt and may disable this feature.
