CI: setup-dotnet downloads fail with HTTP 409 before builds start #456

Resolved — 2026-10-25

Fixed by merged PR #457 (1efec842 on main): all 8 setup steps now request exact SDK 10.0.403, bypassing the failing aka.ms SDK redirect. Linux, macOS, Windows net10.0/net48, CodeQL, format, documentation and package/SBOM checks passed on the fix PR; both automated reviews completed without findings. No production/API/developer SDK-policy change.

PR #455 is updated with main at head e65d5b42 and is running the corrected workflows. Before that update, its rerun also passed all platform tests after the external runtime redirect recovered; its 37 changed executable lines had no missing or partial coverage, confirmed by the CI artifact and Codecov. Checks/reviews of the updated head are being verified separately.

Observed on PR #455, head a5816cd, 2026-10-25 at 20:08 UTC. The PR changes no CI/setup configuration.

Four jobs fail inside the unchanged actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 step, before project build/test/format or CodeQL analysis:

• version
• format
• Analyze C#
• documentation build

install-dotnet.sh resolves the aka.ms links to dotnetorigin.blob.core.windows.net. All three attempts return HTTP 409 for both Runtime 10.0.14 and SDK 10.0.403, ending with Failed to install dotnet. The version failure causes the test matrix and package job to be skipped, so there is no Codecov report.

Local PR validation passed: Release CI build, all 2894 net10 tests, format, net48 build and all nine packages. That does not replace the skipped Windows/coverage CI legs.

Next: retry the failed jobs once; if persistent, investigate installer/feed availability and a reproducible supported setup. Avoid mixing a shared CI repair into the RawCan feature. No SDK/feed policy change has been made.

Retry result

One failed-job retry of all three workflows completed with the same four setup-dotnet failures. Format attempt 2 again returned HTTP 409 for Runtime 10.0.14 and SDK 10.0.403. The test matrix/package jobs were skipped; Windows execution and Codecov remain unverified. Further retries stopped.