Getting a "Qt 5.15 was not found on your system" error

Development
1

Hello,

I’ve been trying to setup Slicer for local development, but I’m having trouble with Qt when going through the configuration step.

I’m running MacOS, and on the build instructions page(macOS — 3D Slicer documentation) there is a link for the Qt installer.

However, in the installer I wasn’t able to find Qt 5.15, even when enabling the archive filter, so I proceeded to install Qt using hombrew.

brew install qt@5

After installation, I tried running the configuration step, like so:

cmake \
  -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=11.0 \
  -DCMAKE_BUILD_TYPE:STRING=Debug \
  -DQt5_DIR:PATH=/opt/homebrew/opt/qt@5/5.15.13_1/lib/cmake/Qt5 \
  ~/Slicer

But I only run into this error:

CMake Error at CMake/SlicerBlockFindQtAndCheckVersion.cmake:30 (message):
  error: Qt 5.15 was not found on your system.You probably need to set the
  Qt5_DIR variable.
Call Stack (most recent call first):
  CMake/SlicerBlockFindQtAndCheckVersion.cmake:67 (__SlicerBlockFindQtAndCheckVersion_find_qt)
  CMakeLists.txt:695 (include)
2

I haven’t built from scratch on a mac in a while and probably the Qt5 version is updated, but usually there’s a specially named file that cmake is looking for (I thought it should be listed in the error message). You can investigate what that file is and make sure the Qt5_DIR variable points to it. You may need to read the cmake code to make sure

3

Thank you for the reply!
I’ll check the cmake files and see if I can figure it out.