[Bryan Chen (bryanchen-d)]

Fixes a flaky Prepare WSL Dev Container smoke tests step on Windows (PR CI Windows / Electron-Smoke (shard 1/3) and def 111 Windows smoke).

Mechanism

• The step installs docker.io and a few packages inside the WSL distro from the Azure Ubuntu mirror (test: use the Azure Ubuntu mirror in the WSL smoke setup #343768). Normally the whole package download takes 2-17 seconds (24 green PR CI jobs sampled over the last 48h).
• Sometimes a connection to the mirror crawls for minutes. apt has no minimum transfer speed, so the download runs past Invoke-Wsl's 300 second timeout. That happened in 2 PR CI runs in the last 48h, both stuck in apt-get install (containerd 28 MB took about 3 minutes in run 41482962880, with Ign: retries in run 41251126966).
• When the mirror is unreachable, apt-get update only warns (W: Failed to fetch … Could not connect to azure.archive.ubuntu.com) and exits 0. The install then fails with E: Unable to locate package docker.io (def 111 main CI 491631).

Fix

• apt-get update --error-on=any, so a failed index fetch fails the attempt instead of being ignored.
• Acquire::http::Timeout "30": a connection that stops sending data fails after 30s, and apt retries it (Acquire::Retries "5"). There is no wall clock on the download itself, so a slow but progressing download gets the whole step budget. The download (--download-only) and a --error-on=any index update (bounded at 45s per attempt) are each retried up to 3 times on error. The final apt-get install installs from the local cache.
• That apt step's Invoke-Wsl budget goes from 300 to 720 seconds to fit the bounded retries. A healthy run still takes seconds.
• This PR's own first CI run hit the slow case (job 125428287654). The indexes downloaded at 8 MB/s, but packages came at about 250 KB/s on every connection, so fresh connections alone don't help. At that rate, 80 MB needs about 320s: more than the old 300s, but within the new budget. The first version of this PR used a 100s cap per attempt, and that kept cutting the crawling containerd and docker.io downloads off mid-file.

Validation

• PowerShell parses the script, and the expanded bash block passes bash -n.
• def 111 Windows CI run 491857 on a proof branch (103334e962) that also refuses the first index update and throttles the first package download to 64 KB/s. Prepare WSL Dev Container smoke tests succeeded. With --error-on=any, the refused update failed attempt 1 instead of warning, and attempt 2 fetched the indexes in 5s. The throttled download ran past 100s on attempt 1, and attempt 2 resumed and finished the remaining 73.4 MB in 1s. Docker then started, and the rest of the setup passed.
• def 111 Windows CI run 491868 on the proof branch for the current design (5904161ba6). It refuses the first index update and throttles the whole package download to 256 KB/s. The step succeeded: attempt 1 of the update failed and attempt 2 passed, then Fetched 79.9 MB in 4min 5s (326 kB/s) completed, which would not fit in the old 300s budget.
• PR CI on the current head: Windows / Electron-Smoke (shard 1/3) passed on the healthy path.

Authored with Copilot

[Bryan Chen (bryanchen-d)]

Ladislau Szomoru (@lszomoru) Christof Marti (@chrmarti) FYI. This bounds and retries the apt step in wslDevContainer.ps1 that #343768 moved to the Azure mirror. The mirror still crawls or refuses connections now and then. #345511 adds Kerberos and squid packages to the same apt-get install line, which means more to download, so the two PRs will conflict on that one line. Whichever lands second only needs to add its packages to $aptPackages.

Co-authored with Copilot

[Copilot]

🟢 Approval recommended

The WSL Dev Container smoke-test setup changes have no active review issues.

No open issues 🎉

What changed in this PR

Improves reliability of the WSL Dev Container smoke-test setup by bounding and retrying apt operations when the Azure Ubuntu mirror stalls or fails.

Changes:

• Makes failed package-index fetches fail the update attempt.
• Retries index updates and download-only installs up to three times, with respective 60- and 100-second limits.
• Raises the WSL command timeout from 300 to 600 seconds to accommodate retries before installation from the package cache.

File	Description
test/​smoke/​wslDevContainer.ps1	Adds bounded apt retries, separates downloading from installation, and extends the setup timeout.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues were identified for the WSL Dev Container apt timeout and retry changes.

No open issues 🎉

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues remain for the WSL dev-container smoke setup changes.

No open issues 🎉

_{Review effort: Balanced}