Warning

Feed-governed motion (G1/G2/G3) requires the following:

A positive G-code feed rate. This can be set with an F word or Gcode::FeedRateSet. Changing the G-code linear units (with G20/G21 or Gcode::UnitsSet) will clear the G-code feed rate and require you to set it again before loading feed-governed motion.
A positive acceleration. This can be set with Gcode::AccelerationRateSet, and is not the same as Robot::PathAccelerationSet.