Possible fix for launcher failing to appear on some Linux systems

While testing the previous PR, I noticed that if stdout is set to None,
the same behaviour is shown as in the following report:
https://forums.ankiweb.net/t/cannot-switch-versions/64565

This leads me to wonder whether IsTerminal is behaving differently
on that user's system, and the use of an env var may be more reliable.

qt/aqt/package.py

@@ -147,6 +147,7 @@ def update_and_restart() -> None:
 
     with contextlib.suppress(ResourceWarning):
         env = os.environ.copy()
+        env["ANKI_LAUNCHER_WANT_TERMINAL"] = "1"
         # fixes a bug where launcher fails to appear if opening it
         # straight after updating
         if "GNOME_TERMINAL_SCREEN" in env:

qt/launcher/addon/__init__.py

@@ -90,6 +90,7 @@ def update_and_restart() -> None:
 
     with contextlib.suppress(ResourceWarning):
         env = os.environ.copy()
+        env["ANKI_LAUNCHER_WANT_TERMINAL"] = "1"
         creationflags = 0
         if sys.platform == "win32":
             creationflags = (

qt/launcher/src/platform/mod.rs

@@ -116,8 +116,9 @@ pub use windows::ensure_terminal_shown;
 pub fn ensure_terminal_shown() -> Result<()> {
     use std::io::IsTerminal;
 
+    let want_terminal = std::env::var("ANKI_LAUNCHER_WANT_TERMINAL").is_ok();
     let stdout_is_terminal = IsTerminal::is_terminal(&std::io::stdout());
-    if !stdout_is_terminal {
+    if want_terminal || !stdout_is_terminal {
         #[cfg(target_os = "macos")]
         mac::relaunch_in_terminal()?;
         #[cfg(not(target_os = "macos"))]