Hello,

in order to get a more meaningful backtrace I've compiled emacs 26.1 directly from its source (source directly downloaded from http://mirror.switch.ch/ftp/mirror/gnu/emacs/emacs-26.1.tar.xz)

The crash remains fully reproducible. I attach you the backtraces. Of yourse, I'm at your disposal for any additional information you may need

Best regards,

Marc