I found a new Z-Machine interpreter today: Kevin Boone’s grotz, a GTK port of frotz.
I haven’t seen it announced anywhere else but it’s worth a look for Linux users wanting to play v6 format Z-Machine games outside of Wine.
FWIW I am the author of the offending object. Well, the author of those bits I didn’t pillage mercilessly from everybody else’s project. There’s a great deal wrong with it, including general incompleteness, but it does sort-of work. There’s a long list of things that need fixing, and which I might be persuaded to fix if there’s any interest, and if it’s not too difficult 