Recently, I was looking for way to skeletonize buffer and besides solution with PostGIS and Postegre solutions there is algortihm
v.voronoi.skeleton. I have tried to use it with different road/rail buffers as described in this tutorial (unfortunatelly in polish, though the best source I got).
Despite following instructions with different parametres and input layers I always get error with output and no layer is created.
2019-07-01T20:50:58 WARNING Duplicate output OUTPUT_HTML_FILE registered for alg build_generic_plot 2019-07-01T20:50:58 WARNING Duplicate output OUTPUT_JSON_FILE registered for alg build_generic_plot