fix(cli): install venv in non-interactive terminals instead of crashing

When stdin is not a TTY (piped input, CI, coding agents) and neither
--yes nor --no-sync is passed, the venv/uv confirmation prompts called
beaupy.select, which raises `termios.error: (25, 'Inappropriate ioctl
for device')`. That error fell through to the generic handler and the
run failed with "Unexpected error" and exit code 1, leaving no venv.

confirm() now detects a non-interactive stdin and returns the prompt's
default (Yes) instead of invoking beaupy, so a non-TTY run installs uv
if missing and runs `uv sync` unattended. --yes and --no-sync behavior
is unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: bjoaquinc

src/dlthub_init/prompts.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import sys
 from typing import cast
 
 import beaupy
@@ -17,8 +18,21 @@ def _echo_selection(value: str) -> None:
     console.print(f"[{CURSOR_STYLE}]{TICK_CHAR}[/{CURSOR_STYLE}] [bold]{value}[/bold]")
 
 
+def _stdin_is_interactive() -> bool:
+    stream = sys.stdin
+    try:
+        return stream is not None and stream.isatty()
+    except (OSError, ValueError):
+        return False
+
+
 def confirm(message: str, *, default: bool = True) -> bool:
     console.print(f"\n[bold]{message}[/bold]")
+    if not _stdin_is_interactive():
+        # No TTY to read a selection from (piped stdin, CI, agents). beaupy would
+        # crash with a termios error, so fall back to the default answer instead.
+        _echo_selection("Yes" if default else "No")
+        return default
     choice = cast(
         str,
         beaupy.select(

tests/test_prompts.py

@@ -8,6 +8,9 @@
 class ConfirmTest(unittest.TestCase):
     def setUp(self):
         display.console.quiet = True
+        interactive = patch("dlthub_init.prompts._stdin_is_interactive", return_value=True)
+        interactive.start()
+        self.addCleanup(interactive.stop)
 
     def tearDown(self):
         display.console.quiet = False
@@ -26,5 +29,22 @@ def test_default_controls_initial_cursor(self, select):
         self.assertEqual(select.call_args.kwargs["cursor_index"], 1)
 
 
+class NonInteractiveConfirmTest(unittest.TestCase):
+    def setUp(self):
+        display.console.quiet = True
+        non_interactive = patch("dlthub_init.prompts._stdin_is_interactive", return_value=False)
+        non_interactive.start()
+        self.addCleanup(non_interactive.stop)
+
+    def tearDown(self):
+        display.console.quiet = False
+
+    @patch("dlthub_init.prompts.beaupy.select")
+    def test_returns_default_without_prompting(self, select):
+        self.assertTrue(confirm("Proceed?", default=True))
+        self.assertFalse(confirm("Proceed?", default=False))
+        select.assert_not_called()
+
+
 if __name__ == "__main__":
     unittest.main()