Hi Harm,
I just filed a bug report http://lilypond.1069038.n5.nabble.com/Wrongly-read-property-with-MetronomeMark-td237659.html
2c2908c905ba822ef656b06b1cc4f0ca33960c9c is the first bad commit commit 2c2908c905ba822ef656b06b1cc4f0ca33960c9c Author: Malte Meyn <lilyp...@maltemeyn.de> Date: Sun Sep 29 10:10:35 2019 +0200
Issue 5563: make edges of brackets dashable The new boolean grob property dashed-edge controls whether the edges of a dashed bracket are solid or dashed. Lukas