bug#53234: terminal URL capability not correctly detected (gnome-terminal 3.22.2).

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hello!

Ludovic Courtès <ludo@gnu.org> writes:

> Hi,
>
> Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:
>
>> I discovered that on a Debian 9 (stretch) box equipped with
>> gnome-terminal 3.22.2, Guix would use terminal ANSI codes to represent
>> hyperlinks in its output, which were not supported by GNOME terminal
>> 3.22.2 which uses VTE 0.46.1 (it picked up support in 3.26 IIRC).
>
> I’m afraid there’s not much we can do: terminal emulators are supposed
> to ignore ANSI sequences they don’t understand.

Ah, thanks for pointing that to me.  I had guessed we had to do some
work to detect the terminal capability and conditionally output escapes
or not, but I'm glad that's not how it works :-).

> My recollection is that there was a bug in libvte back then:
>
>   https://issues.guix.gnu.org/38940#6-lineno18
>
> That bug mentions a much older VTE though, so I wonder if it’s a newer
> regression?

According to [0]:

> At this moment, terminals known to be buggy (OSC 8 resulting in
> display corruption) are VTE versions up to 0.46.2 and 0.48.1, Windows
> Terminal up to 0.9, Emacs's built-in terminal, and screen with 700+
> character long URLs.

Which gnome-terminal shipped with Debian 9 uses.  Luckily, this release
will be EOL in a few months (June 2022) [1], so the problem will
disappear soon.

I'm closing this report, thank you for the explanations!

Maxim

[0]  https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
[1]  https://www.debian.org/releases/stretch/