/usr/share/python3/runtime.d/budgie-dropby-applet.rtupdate is in budgie-dropby-applet 0.4.4-0ubuntu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | #! /bin/sh
set -e
if [ "$1" = rtupdate ]; then
py3clean -p budgie-dropby-applet /usr/lib/budgie-desktop/plugins
py3compile -p budgie-dropby-applet /usr/lib/budgie-desktop/plugins
fi
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