cua-driver maps the agent-cursor overlay as a fullscreen, always-on-top,
all-workspaces X11 window (save-unders composited). When a computer-use
session ends uncleanly — an agent interrupted mid-capture, a stale target
window, a driver error — that window can be left stuck above every app on
every workspace, wedging desktop input until the app is restarted. This
is the same failure class as the HUD's transparent always-on-top window on
Mutter/X11 (#83473), and it bit a real user: an interrupted capture froze
the desktop, the app had to be force-restarted, and the overlay window was
still mapped fullscreen afterwards.
The overlay is cosmetic (a tinted cursor sprite); the driver, captures,
and synthetic input all work without it. `_cua_no_overlay()` already
defaulted it off on macOS (idle CPU redraw loop, #28152/#47032) and
headless/WSL2 Linux; this extends the same auto-detect to X11 desktop
sessions, where raw X11 stacking has no compositor-owned surface to tear
down with the driver's connection. Wayland keeps the overlay: the
compositor owns the layer-surface lifecycle, so a dead driver cannot leave
a stuck top window.
Behavior contract unchanged: an explicit `computer_use.no_overlay: false`
still restores the cursor on any platform, and `true` forces it off.
Tests: X11 (DISPLAY set, no Wayland env) and XDG_SESSION_TYPE=x11
auto-detect off; Wayland keeps the overlay; explicit false overrides
auto-detection on X11.
many tests patched sys.platform or a module's _IS_WINDOWS flag, then
ran on linux ci. the patch selects the branch under test, but the host
does not have the behavior the branch exists for. the test proves the
patch, not the platform. some gated assertions never ran on any host.
this commit adds three markers: linux_only, macos_only, windows_only.
a conftest hook skips a marked test on the other hosts, with a clear
reason. no test fakes a host now. two documented fakes remain
(android/termux, freebsd) because no ci runner exists for them.
each fake site got one of four treatments:
- gate it: the real host supplies the platform; mocks cover real
dependencies only, never host identity
- patch the module's own probe when the subject is the probe's consumer
- assert against the real host when the fake stood in for any non-x host
- delete the patch when it set the value the host already has
bare skipif(sys.platform != ...) guards became markers too. the lane
model skips these on linux and never imports them on windows, so they
ran on no host. platform parametrize tables are now one marked test
per os.
running on real hosts found real errors: a chrome-sandbox failure in
test_gui_command that main hides, and two windows failures fixed here.
the agents.md testing section now documents the policy.
Second, deeper pass over tools/gateway/hermes_cli plus first pass over
the trees wave 1 missed (acp, acp_adapter, skills, computer_use, docker,
dashboard, conformance, monitoring, secret_sources, hermes_state,
providers). Same rubric as wave 1 (AGENTS.md test policy); security,
alternation/caching invariants, issue-number regressions, and E2E kept.
Real test-quality fixes found and rooted out along the way:
- tests/tools/test_command_guards.py made real auxiliary-LLM HTTPS calls
(DEFAULT_CONFIG smart-approval leaked in) — pinned approval
mode=manual via autouse fixture: 17.4s → 0.4s.
- test_model_switch_custom_providers.py / test_user_providers_model_switch.py
silently probed live provider catalogs (~2s/test) — stubbed
cached_provider_model_ids/provider_model_ids/fetch_api_models.
- test_telegram_noise_filter.py: 15-platform copy-paste matrix over
shared gateway.run logic → 3 representative platforms (55s → 3.9s).
- test_gateway_shutdown.py: stop()'s 5s interrupt-deadline loop spun on
MagicMock agents — interrupt.side_effect now clears _running_agents
(22s → 1.0s).
- test_gateway_inactivity_timeout.py poll-harness timings shrunk 3-5x
(24s → 1.1s); test_mcp_stability.py backoff/SIGTERM-grace sleeps
patched (15.4s → 2.5s); test_async_delegation.py negative-drain wait
5s → 0.5s.
- test_telegram_init_deadline.py: loop-block margin restored to 1.0s
with rationale comment — the watchdog-dump assertion needs the loop
blocked well past deadline+grace under parallel load (flaked once in
the 40-worker verification run at a 0.2s margin).
Verification: full hermetic suite via scripts/run_tests.sh —
2,438 files, 21,718 tests passed, 0 failed, 293.9s wall.
Suite totals vs original baseline: 46,820 → 19,757 test functions
(−57.8%), wall 583.5s → 293.9s (−50%), subprocess CPU 13,564s → 11,623s.
Auto-detect now disables the cursor overlay on darwin as well as
headless/WSL2 Linux. After start_session, also call
set_agent_cursor_enabled(false) when the policy is on so older drivers
without --no-overlay still tear the overlay down.
Co-authored-by: David Metcalfe <80915+DavidMetcalfe@users.noreply.github.com>
The hermes-sweeper review #4701565902 (2026-07-15) flagged two
consistency issues in `_cua_driver_supports_no_overlay` and one
additive-config concern:
1. `cua-backend.py:260` — the `cua-driver --help` support probe
inherited the full parent environment. cua-driver is a third-party
binary; every other spawn site in this file (manifest probe at
`:214`, MCP spawn at `:697`, install probe at `:997`) uses
`_sanitize_subprocess_env(cua_driver_child_env())`. The `--help`
probe should match. This was a low-impact leak (only help output
exits), but inconsistency is the wrong default for a third-party
subprocess.
2. `cua_backend.py:238` — when the manifest returned a `command`
different from the input `driver_cmd` parameter (e.g. a relocated
executable at `/opt/relocated/cua-driver` while the system binary
is at `/usr/bin/cua-driver`), the support probe ran against
`_CUA_DRIVER_CMD` (the default) instead of the manifest-discovered
`command`. Two failure modes:
- The wrapper binary supports `--no-overlay` but the system binary
doesn't → probe returns False → overlay kept despite capability.
- The system binary supports `--no-overlay` but the wrapper doesn't
→ probe returns True → MCP spawn crashes on the unknown flag.
3. The original commit bumped `_config_version` 31→32 for an additive
default (`computer_use.no_overlay: None`). AGENTS.md specifies that
additive defaults in existing sections are handled by deep merge
and should NOT trigger a version bump. After cherry-picking onto
current `origin/main` (which is already at 33), the bump is
effectively dropped — resolved to main's 33.
Changes:
- Add `env=_sanitize_subprocess_env(cua_driver_child_env())` to the
`--help` subprocess (with the same import + rationale comment as
the manifest probe).
- Pass `driver_cmd=command` (or `driver_cmd=driver_cmd` for the
fallback path) into `_mcp_args_with_overlay_flag`, so the support
probe runs against the binary that will actually be launched.
Tests (3 new):
- `test_help_probe_passes_sanitized_env` — verifies `subprocess.run`
is called with an `env=` kwarg.
- `test_manifest_command_drives_support_probe` — verifies the probe
runs against the manifest command when it differs from the input
driver_cmd.
- `test_fallback_uses_input_driver_cmd_for_support_probe` — verifies
the fallback path (no command in manifest) uses the input
driver_cmd.
- `test_probe_distinguishes_support_between_binaries` — sanity check
that the lru_cache key on `driver_cmd` prevents cross-binary
cache leakage.
File-revert negative test confirmed all three of the new
"manifest/probe" tests are load-bearing: with the pre-fix code, they
fail (probe runs against the default binary instead of the resolved
one); with the fix, they pass. 20/20 tests in
`tests/computer_use/test_cua_no_overlay.py` green.
`TestMcpInvocationResolution` (8/8) still green.
Refs: sweeper review #4701565902
Address review feedback from cross-vendor review (Flash + GPT-OSS):
1. Auto-detect now checks for headless Linux (no DISPLAY), WSL2
(/proc/version contains 'microsoft'), instead of all Linux.
Desktop Linux with a compositor keeps the overlay.
2. Add _cua_driver_supports_no_overlay() that probes cua-driver --help
to check if the flag is supported. Older drivers (< 0.6.x) reject
unknown flags, so passing --no-overlay would crash the MCP spawn.
3. Update tests to cover headless vs desktop Linux, WSL2 detection,
version probe, and the unsupported-driver fallback path.
- Add autouse fixture to TestMcpInvocationResolution to disable
--no-overlay flag so existing tests assert baseline args
- Make test_config_load_failure_fails_safe and test_missing_section_enables
platform-aware (Linux auto-detect returns True, macOS/Windows False)
cua-driver's cursor overlay rendering loop can consume CPU indefinitely
when idle (#28152, #47032). On Linux/WSL2, the overlay serves no visual
purpose and the rendering path is the primary source of idle CPU usage.
Add computer_use.no_overlay config option (default: auto-detect) that
passes --no-overlay to cua-driver when enabled. Auto-detection disables
the overlay on Linux (covers WSL2, headless, containers) where it has no
benefit, and keeps it enabled on macOS/Windows where it is visually
useful.
Refs: #28152, #47032
cvillarroel2