resource files generated by Qt's resource compiler (rcc) depend on mtimes of the input files, which may have been generated at build time. . There is an upstream bug https://bugreports.qt.io/browse/QTBUG-62511 and a corresponding merged pull request https://codereview.qt-project.org/202999. . A temporary solution is to add '--format-version 1' to the rcc command line.
Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).