Logging always produces terminal escape sequences, even when printing to file or pipe

[sleeptightAnsiC]

Gamescope always produces logs with terminal sequences such as \e[0;34m and \e[0m, even when it prints them into non-tty (not an interactive terminal) such as file or pipe. This makes it hard to read those logs with text editor, or to parse them with external command.

Most command line utilities usually deal with this problem by checking stderr with isatty(3). In gamescope those sequences appear to be hard-coded here LogScope::log and here GetLogPriorityText

Repro:

$ git clone --recursive https://github.com/ValveSoftware/gamescope.git
$ cd gamescope
$ meson setup build/
$ ninja -C build/
$ build/src/gamescope -- wine winemine 2> sample.txt   # can be anything, I just used 'wine winemine'
$ xdg-open sample.txt

Result:

Expected: Terminal escape sequences should be omitted in this case.

Enviroment:

$ build/src/gamescope --version
[gamescope] [Info]  console: gamescope version 3.16.1-39-gbafa157 (gcc 14.2.1)
$ uname -a
Linux MAL200424 6.13.2-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 08 Feb 2025 18:54:55 +0000 x86_64 GNU/Linux