'Run with Profiler' requires a manual install of sysprof, but should it?
Xubuntu 19.04 running in a QEMU/KVM vm.
Gnome Builder 3.32.1 flatpak-stable
Sysprof 'Run with Profiler' in the 'Run Options' menu will not run without a manual install.
The message "Sysprof requires authorization to access your computers performance counters." (computers should be computer's, a possessive) is given without showing the authentication window as is done when running 'Run with Profiler' after sysprof is installed via apt.
sudo apt install sysprof
The message appears to be from https://github.com/GNOME/sysprof/blob/master/lib/sources/sp-perf-source.c line 664.
Valgrind will run, 'Run with Valgrind' from the same menu but is not installed outside of flatpak as is required with sysprof in order for 'Run with Profiler' to work.
There are some files for sysprof in /var/lib/flatpak and a grep of the gnome-builder project shows sysprof lines.