[PATCH] terminal: Show a warning when launched terminal quickly exits

[Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>]

Terminals quitting in less than one second are likely the result of a
failure to execute the launched command: show a warning including the
command that was launched, so the user can try to debug this.

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
I recently had issues launching devshell because of some environment
variables containing unsupported chars. While my specific issue probably
has to be fixed on the bitbake side [1], it was a bit tricky to
understand because no error was shown and the fail was so quick that I
was never able to see any terminal window popping.

Adding a warning in such a case should help the user to understand what
is going wrong.

[1]: https://lore.kernel.org/r/20251114-mathieu-back_quote_devshell-v1-0-45e83df2f362@bootlin.com
---
 meta/lib/oe/terminal.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/meta/lib/oe/terminal.py b/meta/lib/oe/terminal.py
index 4412bc14c1d1..068269018dbb 100644
--- a/meta/lib/oe/terminal.py
+++ b/meta/lib/oe/terminal.py
@@ -240,6 +240,7 @@ def spawn(name, sh_cmd, title=None, env=None, d=None):
     import tempfile
     import time
     pidfile = tempfile.NamedTemporaryFile(delete = False).name
+    start_time = None
     try:
         sh_cmd = bb.utils.which(os.getenv('PATH'), "oe-gnome-terminal-phonehome") + " " + pidfile + " " + sh_cmd
         pipe = terminal(sh_cmd, title, env, d)
@@ -249,6 +250,7 @@ def spawn(name, sh_cmd, title=None, env=None, d=None):
         if pipe.returncode != 0:
             raise ExecutionError(sh_cmd, pipe.returncode, output)
 
+        start_time = time.time()
         while os.stat(pidfile).st_size <= 0:
             time.sleep(0.01)
             continue
@@ -262,7 +264,10 @@ def spawn(name, sh_cmd, title=None, env=None, d=None):
             os.kill(pid, 0)
             time.sleep(0.1)
         except OSError:
-           return
+            if start_time and (time.time() - start_time < 1):
+                bb.warn("Terminal \"%s\" started but stopped only after %.2fs while running \"%s\""
+                        % (name, time.time() - start_time, sh_cmd))
+            return
 
 def check_tmux_version(desired):
     vernum = check_terminal_version("tmux")

---
base-commit: e556df28f47e754b53e1f46c97dde2b19fd8fad1
change-id: 20251114-mathieu-too_quick_devshell-c9085d3538f0

Best regards,
-- 
Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>