Qt Creator crashes when too many old Qt versions are installed

Testing the Qt 5.9.7 Android packages, and opening the "Qt Quick Controls 2 - Gallery" example caused a crash with the error messages:

Failed to initialize custom project wizard in /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/codesnippet: Cannot open /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/codesnippet/wizard.xml: Too many open files
Failed to initialize custom project wizard in /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/qtcreatorplugin: Cannot open /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/qtcreatorplugin/wizard.xml: Too many open files
Failed to initialize custom project wizard in /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/qtquick2-extension: Cannot open /home/paul/Qt/Tools/QtCreator/share/qtcreator/templates/wizards/qtquick2-extension/wizard.xml: Too many open files

(process:2134): GLib-ERROR **: 10:32:24.671: Creating pipes for GWakeup: Too many open files

ConnectionServer error: "QLocalSocket: Remote closed" "/tmp/QtCreator-GkNjql/ClangBackEnd-2134"
Trace/breakpoint trap (core dumped)

This is an installation that contains a number of old Qt versions, and it looks like Creator is opening a lot of files from each version. I have attached a filtered strace log showing all the openat() calls.