Add copilot skill based on ci-analysis

[Copilot]

Adds a ci-analysis copilot skill to the dotnet/diagnostics repository, adapted from the ci-analysis skill in dotnet/runtime (PR dotnet/runtime#123913).

What's Included

• .github/skills/ci-analysis/SKILL.md — Main skill documentation describing when and how to use the CI analysis skill, including three operation modes (PR analysis, Build ID, Helix Job), interpretation guidelines, and recommendation generation workflow.
• .github/skills/ci-analysis/scripts/Get-CIStatus.ps1 — PowerShell script that queries Azure DevOps builds, Helix test failures, extracts console logs, correlates failures with PR changes, and provides structured JSON summaries.
• .github/skills/ci-analysis/references/ — Eight reference documents:
  • azdo-helix-reference.md — AzDO/Helix details with diagnostics pipeline info
  • helix-artifacts.md — Guide to Helix work item artifacts
  • manual-investigation.md — Manual investigation steps
  • azure-cli.md — Azure CLI deep investigation
  • binlog-comparison.md — Binlog comparison patterns
  • build-progression-analysis.md — Build progression analysis
  • delegation-patterns.md — Subagent delegation patterns
  • sql-tracking.md — SQL tracking for investigations

Key Adaptations for diagnostics

• Default repository changed from dotnet/runtime to dotnet/diagnostics
• Pipeline references updated to dotnet-diagnostics and dotnet-diagnostics-official
• Note added that Known Build Error tracking is not currently set up in this repo
• Quick start examples updated with diagnostics-appropriate repositories

Original prompt

Lets add a copilot skill based on the ci-analysis skill in the dotnet/runtime repo. See the PR that added that skill: dotnet/runtime#123913

The relevant skill in the dotnet/diagnostics repo will be similar but not exactly the same as we don't have known failures set up in this repo.

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[max-charlamb]

@copilot , you didn't seem to implement this

[Copilot]

@copilot , you didn't seem to implement this

Implemented in 5781cec. Added the full ci-analysis skill adapted from dotnet/runtime, including:

• SKILL.md with diagnostics-specific defaults
• Get-CIStatus.ps1 script (defaults to dotnet/diagnostics)
• All reference docs (azdo-helix-reference, helix-artifacts, manual-investigation, azure-cli, binlog-comparison, build-progression-analysis, delegation-patterns, sql-tracking)

Key adaptations: default repo is dotnet/diagnostics, pipeline references updated (dotnet-diagnostics, dotnet-diagnostics-official), and a note that Known Build Error tracking isn't set up in this repo.

[max-charlamb]

@copilot please investigate failures in #5691

[Copilot]

@copilot please investigate failures in #5691

CI Analysis for PR #5691

Verdict: All failures are PR-related. This is a WIP PR (marked as such in the title) that migrates System.CommandLine from 2.0.0-beta5 to 2.0.2 GA. The PR author explicitly states "Does Not Build - Breaking API Changes Required". No AzDO CI builds were triggered (the PR is in draft status).

Root cause — incomplete API migration across 5 breaking changes:

1. parseResult.Configuration.Output/Error removed — The PR partially migrated SetAction handlers to use context.Console.Out/Error in some files (dotnet-dump, dotnet-sos, dotnet-stack, dotnet-trace, ProcessStatus), but the CommandService.cs migration (removing CommandLineConfiguration constructor) left its help generation system broken because HelpBuilder/HelpContext are now internal.

2. HelpBuilder/HelpContext now internal — CommandService.cs uses new HelpBuilder(maxWidth) and new HelpContext(...) which are no longer public in 2.0.2. This requires finding an alternative approach for help text generation.

3. ProcessTerminationTimeout removed — ProcessTerminationHandler.cs was only commented out (the property access), not properly replaced with the new API equivalent.

4. CommandLineConfiguration constructor changed — CommandService.cs was partially migrated (removed the constructor) but the replacement _rootCommand.Parse() doesn't set up Output/Error redirection, breaking console output routing for the debug services.

5. Not all tools migrated — Files in dotnet-counters, dotnet-dsrouter, and dotnet-gcdump still need SetAction handler updates.

Recommended actions:

1. This PR needs significant additional work (~2-3 days per the PR author) to complete the migration
2. No CI retry needed — the build won't pass until the API migration is complete
3. The team should evaluate whether the beta5 version poses actual issues before investing in this migration

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dev.azure.com
  • Triggering command: /usr/bin/curl curl -s REDACTED (dns block)
  • Triggering command: /usr/bin/curl curl -sv REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[noahfalk]

This looked good to me whenever you think its ready.