I used to build and package Qt modules in a way similar to what COIN is doing:

1. Qt is installed in /home/qt/work/install/
2. I build a Qt module using /home/qt/work/install/bin/qt-configure-module <path to module>
3. Finally I run cmake --install . --prefix /home/qt/work/install_root

However, since v6.8.1, this does not work anymore.
During the cmake --install step it fails during SBOM generation. I have tested with multiple Qt modules and they all failed. Here is the output for QtWebEngine:

-- Starting SBOM generation in build dir: /home/qt/work/build/qt_sbom/staging-qtwebengine.spdx.in
CMake Error at qt_sbom/SPDXRef-PackagedFile-qt-module-WebEngineCore.cmake:5 (message):
  Cannot find 'lib/libQt6WebEngineCore.so.6.8.1' to compute its checksum.
  Expected to find it at
  '/home/qt/work/install/lib/libQt6WebEngineCore.so.6.8.1'
Call Stack (most recent call first):
  qt_sbom/assemble_sbom.cmake:14 (include)
  cmake_install.cmake:133 (include)

In other word the SBOM generation is looking for libQt6WebEngineCore.so.6.8.1 in the Qt install directory, not in the module install directory, disregarding the {{--prefix)) option.

It seems there are 2 ways to mitigate the issue:

1. Run cmake -install without prefix before running it with -prefix, this is what COIN is doing
2. Set -no-sbom when calling qt-configure-module. For some reason setting -no-sbom during the initial configure is not carried over to modules that are built later with qt-configure-module