Comment 3 for bug 1593963

Reproduced with Inkscape 0.92pre1 (prerelease tarball) and latest trunk r14995 on OS X 10.7.5.

One trigger here (based on a few quick tests) seems to be cusp end nodes (with retracted handles) of curved segments (e.g. a 3-node path drawn with the pen tool (mode: bezier path; shape: None), with a smooth node in the middle, and cusp nodes (no extracted handles) as start and end node): either Inkscape freezes immediately when applying the path effect, or later when dragging start and end nodes a few times with the mouse after having adjusted the width with one of the powerstroke knots.