Add 'session not created' to Chrome driver retry error snippets#1575
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ilonatommy merged 1 commit intomainfrom Mar 23, 2026
Merged
Add 'session not created' to Chrome driver retry error snippets#1575ilonatommy merged 1 commit intomainfrom
ilonatommy merged 1 commit intomainfrom
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The retry logic in GetChromiumDriver catches transient Chrome startup
failures and retries up to 3 times. However, the error snippet list
missed the broad 'session not created' pattern, which covers several
Chrome crash variants including:
session not created: Chrome instance exited.
session not created: Chrome failed to start: crashed.
The existing snippets ('exited abnormally', 'failed to start', etc.)
have been added reactively over time as new error messages surfaced.
Adding 'session not created' as a broader pattern covers current and
future variants of this class of transient Chrome startup failure.
Observed in dotnet/runtime#125566 (Chrome 146 bump) where 2 of 202
Helix work items failed with 'session not created: Chrome instance
exited' — the retry never fired because no snippet matched.
Co-authored-by: Copilot <[email protected]>
maraf
approved these changes
Mar 23, 2026
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Problem
The retry logic in
GetChromiumDrivercatches transient Chrome startup failures and retries up to 3 times, matching error messages against a list of known snippets:exited abnormallyCannot start the driver servicefailed to startDevToolsActivePort file doesn't existHowever, Chrome can also crash during session creation with error messages like:
This error doesn't match any of the existing snippets, so the retry logic never fires and the test fails immediately.
Context
Observed in dotnet/runtime#125566 (Chrome version bump to 146.0.7680.80), where 2 of 202 Helix work items failed with this error but also on the next bump PR and other runtime PRs. The existing snippets have been added reactively over the years as new Chrome crash messages appeared (see #513, #656, #1563).
Fix
Add
session not createdas a broader error snippet. This covers:session not created: Chrome instance exited.(the immediate trigger)session not created: Chrome failed to start: crashed.(already partially covered byfailed to start)session not created: ...variantsThis is intentionally broader than adding just
Chrome instance exitedto avoid the pattern of chasing individual error messages.