Hey there, let's fix that frustrating error you're hitting when building your first Qt Quick Controls app on Ubuntu 16. This is a super common issue, almost always tied to missing Qt development packages that aren't included in a default setup. Here's how to get it sorted:

1. 先安装缺失的Qt开发依赖包 #

Ubuntu 16's software repository splits Qt modules into separate packages, so you'll need to explicitly install the ones for QML and Quick. Open a terminal and run these commands:

sudo apt-get update
sudo apt-get install qtdeclarative5-dev qtquickcontrols2-5-dev

A quick breakdown:

• qtdeclarative5-dev covers the core QML module's headers and libraries, which is required for the qml module reference
• qtquickcontrols2-5-dev is for Qt Quick Controls 2. If your project uses the older Controls 1, swap this for qtquickcontrols5-dev instead.

2. Check Qt Creator's Kit Configuration #

If the error persists after installing packages, Qt Creator might not be picking up the newly installed modules. Let's verify your setup:

• Open Qt Creator, go to Tools → Options from the top menu
• Select Build & Run on the left, then switch to the Kits tab
• Pick the kit you're using (usually something like "Desktop Qt 5.x.x GCC 64bit") and click Details on the right
• Check that the Qt Version points to the correct qmake executable. If it looks off, click Manage next to Qt Version
• On the Qt Versions page, select your Qt 5 installation and click Refresh—this should force Qt Creator to scan for all installed modules, including qml and quick
• If the modules still don't show up, manually point to the default Ubuntu 16 qmake path: /usr/lib/x86_64-linux-gnu/qt5/bin/qmake

3. Verify qmake Can Detect the Modules #

To rule out system-level issues, test qmake directly in the terminal:
First, check if the QML installation path is recognized:

qmake -query QT_INSTALL_QML

You should get a valid path like /usr/lib/x86_64-linux-gnu/qt5/qml. Then list all available modules:

qmake -qt=qt5 -modules

Look for qml and quick in the output. If they're present, the problem is definitely in Qt Creator's kit configuration—just refresh it again as step 2 describes.

4. Last Resort: Manually Specify Module Path (Rarely Needed) #

If everything else fails, you can explicitly add the module path to your project's .pro file, though this shouldn't be necessary if you installed the packages correctly:

QT += qml quick
QML_IMPORT_PATH += /usr/lib/x86_64-linux-gnu/qt5/qml

内容的提问来源于stack exchange，提问作者vico