This syntax is allowed as of Fish 3.4.0 The issue on upgrade was described in https://github.com/fish-shell/fish-shell/issues/8778 and Fish reverted `fish_title` to the old syntax in https://github.com/fish-shell/fish-shell/commit/c5a8764db1c94f386f0546bd9a25ea3520eb15b8 due to upgrade issues.
- Bug#1008149: nodejs: Unable to install nodejs 16.13.2+real... Kyle Robbertze
- Bug#1008149: Acknowledgement (nodejs: Unable to insta... Kyle Robbertze
- Bug#1008149: Michel Le Bihan
