it's 1018
   my touchpad is broken. this happened on its own for some reason while I
   wasn't using the system over the past 3-4 months.
   so maybe i'll download the release from the terminal.
   1020
   [1]https://github.com/phhusson/treble_experimentations/releases
   january 18, 2021
   1022
   it looks like the last tag before that date was v300.l
   4a95e7a81499a39bc58844edfa54d94e5c5f42d9 (hand-copied)
   so it makes sense it didn't work, as treble_experimentations is past
   v400 now.
   1025
   ok, the v300 releases are for roar, and the instructions say to
   download quack :(

References

   1. https://github.com/phhusson/treble_experimentations/releases