fix(voice): fallback to binary check when pm is unavailable in Termux (#31015)

[dskwe]

Problem

/voice on in Termux reports "Termux:API Android app is not installed" even when both the termux-api CLI package and the Termux:API Android app are installed and functional. Users confirm termux-microphone-record works from the command line.

Closes #31015

Root Cause

_termux_api_app_installed() relies exclusively on pm list packages com.termux.api to detect the companion Android app. In many Termux setups pm is either not on PATH or the Termux process lacks permission to invoke the Android package manager, causing the check to return False regardless of whether the app is installed.

Fix

Add a fallback in _termux_api_app_installed(): when pm fails (not found, permission denied, timeout, etc.), check whether termux-microphone-record binary exists via shutil.which(). The termux-api CLI package is a thin wrapper that only functions when the companion Android app is installed, so the binary's presence is a reliable proxy.

No behavioral change for environments where pm works correctly.

Design Rationale

The fix uses a simple two-step fallback: if pm list packages confirms the app, return True (back-compat). If pm fails for any reason (not on PATH, permission denied, timeout), fall back to checking whether termux-microphone-record is on PATH.

The key tradeoff vs a multi-probe approach: when pm returns clean but empty output (some devices do this due to permission restrictions even when the app is installed), a "definitive miss" branch would return False — same false-negative shape as the original #31015 bug. Our fallback avoids this by trusting the binary when pm is inconclusive.

The false-positive case (CLI installed without app) is rare — pkg install termux-api prompts for the companion app — and surfaces a precise runtime error from termux-microphone-record itself, which is more actionable than a pre-check denial.

Changes

• tools/voice_mode.py — _termux_api_app_installed() adds fallback to shutil.which("termux-microphone-record") when pm fails. Same public signature and return type.
• tests/tools/test_voice_mode.py — 13 new tests in two classes:
  • TestTermuxApiAppInstalledFallback (8 tests): unit-level truth table for _termux_api_app_installed covering pm finds package, pm not found/permission denied/timeout/non-zero + binary present, pm fails + binary absent, non-Termux environment.
  • TestDetectAudioEnvironmentTermuxFallback (5 tests): end-to-end through detect_audio_environment confirming the misleading "app not installed" warning no longer fires when pm fails but the binary works.

How to Test

# New regression tests (13 tests)
python -m pytest tests/tools/test_voice_mode.py -k "Fallback or TermuxFallback" -v

# All voice mode tests
python -m pytest tests/tools/test_voice_mode.py -v

[alt-glitch]

Competing PR: #31028 also fixes #31015 with a more comprehensive graded detection ladder. Both modify tools/voice_mode.py.

[dskwe]

Competing PR: #31028 also fixes #31015 with a more comprehensive graded detection ladder. Both modify tools/voice_mode.py.

Design rationale

The fix uses a simple two-step fallback: if pm list packages confirms the app, return True (back-compat). If pm fails for any reason (not on PATH, permission denied, timeout), fall back to checking whether termux-microphone-record is on PATH.

The key tradeoff vs a multi-probe approach: when pm returns clean but empty output (some devices do this due to permission restrictions even when the app is installed), a "definitive miss" branch would return False — same false-negative shape as the original #31015 bug. Our fallback avoids this by trusting the binary when pm is inconclusive.

The false-positive case (CLI installed without app) is rare — pkg install termux-api prompts for the companion app — and surfaces a precise runtime error from termux-microphone-record itself, which is more actionable than a pre-check denial.

[teknium1]

Thanks for isolating the Termux false-negative; current main still has the single pm gate at tools/voice_mode.py:68-82, so the reported failure remains actionable.

Problems

• tools/voice_mode.py:91 falls back to shutil.which() after a clean pm invocation that simply did not list com.termux.api, not only after an unavailable or failed pm. That bypasses the Android-app gate introduced in commit c3141429b, including the runtime gate at current-main tools/voice_mode.py:370.
• The new tests do not cover the clean-miss-plus-binary case. Current main explicitly preserves the no-app block in tests/tools/test_voice_mode.py:309-323.

Suggested changes

• Distinguish a failed/non-zero pm probe from a clean package miss; use the binary fallback only for the former, or add a stronger independent probe before treating the latter as available.
• Add direct and environment-level coverage for a zero-exit empty pm result with the binary present.

Automated hermes-sweeper review.

[teknium1]

This fallback also runs when pm completed successfully but did not list the app. That bypasses main's explicit CLI-without-Android-app block; limit the fallback to an exception/non-zero probe result (or add a separate authoritative probe), and add a clean-miss-plus-binary regression test.

[teknium1]

The Termux:API detection fix landed in #73520 via your/#31028's probe-ladder version (this PR was its dupe). Thanks!

(Landed via #73520, merge e04c2a9ebd.) Closing.