Gnome Terminal 3.18.3 + VTE 0.42.5

@dfandrich is this only because of an older gnome terminal and we can just ask users to run a later version or is there anything more clever we can here?

OSC 8 support was added to Gnome Terminal 6 years ago in ver. 3.25.1. There's a list tracking support in terminal emulators on this page. The OSC 8 spec also says

Any terminal that correctly implements OSC parsing according to ECMA-48 is guaranteed not to suffer from compatibility issues. That is, even if explicit hyperlinks aren't supported, the target URI is silently ignored and the supposed-to-be-visible text is displayed, without artifacts.

It sounds like there may have been a bug in Gnome Terminal that didn't do this, but other terminal emulators, even those that don't support OSC 8, should ignore the extra data and that is what I found in my testing. That spec page lists four terminal emulators that still didn't work properly as of 3 years ago, but all of them are working (mostly) today in their latest versions.

I can't think how we could easily and reliably detect whether a terminal emulator is buggy or not and dynamically enable this. xterm-style answerback strings might theoretically do it if those were still a thing, otherwise it would take linking with an X11 library and even that wouldn't work all the time. My suggestion would be to just use --no-styled-output on those few cases where it doesn't work, or better yet, upgrade your terminal emulator since there aren't any known buggy implementations left according to that page.

That page also says VTE versions up to 0.48.1 (6 years ago) have bugs so I've submitted #11071 to test VTE_VERSION env var