[Bug] v1.0.49: ~20s startup freeze before ICU native addon loads (Linux, D-Bus/keytar regression)

[jeziellopes]

Describe the bug

Since upgrading from v1.0.48 → v1.0.49, every interactive copilot session on native Linux hangs for ~20 seconds before the CLI prompt appears. The CLI does eventually start — it is not fully blocked like the WSL variant in #3385 — but every session has an unavoidable 20-second wait.

The freeze is isolated to the window between Starting Copilot CLI and ICU native addon loaded in the session log. This window was ~0.3s in v1.0.48 and is consistently ~20s in v1.0.49.

Root cause (confirmed via strace): v1.0.49 moved a D-Bus session bus / credential lookup (likely node-keytar / libsecret) onto the critical startup path before icu-native.node is loaded. The lookup uses a 0.5s + 15s retry/timeout pattern and only exits (giving up) after ~15.5s. Multiple worker threads are blocked waiting on the same futex. In v1.0.48 this lookup happened after ICU, so it was off the critical path.

Affected version

GitHub Copilot CLI 1.0.49

Steps to reproduce

1. Install or auto-update to v1.0.49 on Linux.
2. Run copilot interactively.
3. Observe ~20s delay before the CLI prompt appears.

Expected behavior

Startup should complete in under 1 second (as in v1.0.48).

Root cause (strace analysis)

A strace -f trace captured the exact blocking sequence:

11:29:23.721  Worker thread connects to D-Bus session bus /run/user/1001/bus
11:29:23.722  D-Bus auth succeeds (REJECTED EXTERNAL → OK → AGREE_UNIX_FD)
11:29:23.724  futex_wait(timeout=0.5s)  → ETIMEDOUT  ← credential lookup attempt 1
11:29:24.224  futex_wait(timeout=15.0s) → ETIMEDOUT  ← credential lookup attempt 2
11:29:39.224  Thread exits with 0 (gave up after 15.5s)
              [+4.8s for blocked worker threads to drain]
11:29:44.019  icu-native.node finally loaded  ← CLI becomes usable

The D-Bus secret service is reachable (auth succeeds in <1ms) but the GetSecret/FindItems call never returns within either timeout window. All startup worker threads block on the same futex waiting for the result.

• v1.0.48: credential lookup happened after icu-native.node loaded → off critical path
• v1.0.49: credential lookup happens before → blocks all of startup for ~20s

Observed behavior

Downgrading back to v1.0.48 on the same machine restores instant startup, confirming this is a pure v1.0.49 regression and not system-specific.

# v1.0.48 — instant (before auto-update)
2026-05-19T00:10:31.256Z [INFO] Starting Copilot CLI: 1.0.48
2026-05-19T00:10:31.543Z [INFO] ICU native addon loaded        ← 0.3s later

# v1.0.49 — 20s freeze (after auto-update)
2026-05-19T00:12:49.143Z [INFO] Starting Copilot CLI: 1.0.49
2026-05-19T00:13:09.456Z [INFO] ICU native addon loaded        ← 20.3s later

# v1.0.48 — instant again (after manual downgrade, same machine)
2026-05-20T14:59:27.126Z [INFO] Starting Copilot CLI: 1.0.48
2026-05-20T14:59:27.377Z [INFO] ICU native addon loaded        ← 0.25s later

Across 20+ consecutive v1.0.49 sessions the delta was consistently 20–23s.

Environment

• OS: Ubuntu 22.04.5 LTS (Jammy Jellyfish)
• Kernel: 6.8.0-111-generic
• Arch: x86_64
• Shell: zsh
• Node.js (bundled in SEA): v24.15.0
• Binary: Single Executable Application, ~/.local/bin/copilot (154 MB)

What I've ruled out

Candidate	Result
MCP servers	Disabled all, freeze persists
SQLite WAL bloat	VACUUM + TRUNCATE applied, no effect
Stale lock files	Cleaned, no effect
Node compile cache (cold)	Added NODE_COMPILE_CACHE, no effect
runtime.node cold page cache	Pre-warmed, no effect
gnome-keyring / DBus ping	DBus responds in 9ms — service is alive and healthy
Git repository in cwd	NOT the cause — git detection happens after ICU loads
HTTPS to api.github.com	Non-blocking (EINPROGRESS), not on critical path

Workaround

Pin to v1.0.48 and disable auto-update:

export COPILOT_AUTO_UPDATE=false
# Download v1.0.48 from https://github.com/github/copilot-cli/releases/tag/v1.0.48
# (copilot-linux-x64.tar.gz) and replace your current binary

Related issues

• [Bug] Can't running copilot cli 1.0.49 on wsl after upgrade copilot #3385 — WSL variant: fully blocked on v1.0.49 (same root cause, more severe)
• Bash tool breaks on NixOS with version >=1.0.49 #3392 — Bash tool breaks on NixOS ≥1.0.49
• Regression: $EDITOR missing keystrokes starting from v1.0.49 #3420 — Regression: $EDITOR missing keystrokes starting from v1.0.49

Suggested fix

Move the credential/keytar lookup back to an async/deferred path that does not block icu-native.node initialization (as it was in v1.0.48), or reduce the 15s fallback timeout for the "secret not found" case.