Pester Failure Analysis
PowerShell/PowerShell
Investigates failing Pester tests in PowerShell CI jobs by following a six-step workflow from pull request status to documented fix recommendations.
Systematic debugging workflow for test failures. An agent skill from microsoft/haste.
Install Debug Test Failures
$ npx skills add microsoft/haste --skill debug-test-failures -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install microsoft/haste debug-test-failures --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.github/skills/debug-test-failures .claude/skills/debug-test-failures && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .claude/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failuresType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add microsoft/haste --skill debug-test-failures -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install microsoft/haste debug-test-failures --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.github/skills/debug-test-failures .agents/skills/debug-test-failures && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .agents/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/haste --skill debug-test-failures -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install microsoft/haste debug-test-failures --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.github/skills/debug-test-failures .cursor/skills/debug-test-failures && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .cursor/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/microsoft/haste.git --path .github/skills/debug-test-failures--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add microsoft/haste --skill debug-test-failures -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install microsoft/haste debug-test-failures --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.github/skills/debug-test-failures .gemini/skills/debug-test-failures && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .gemini/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install microsoft/haste debug-test-failuresInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add microsoft/haste --skill debug-test-failures -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .github/skills && cp -r skills-src/.github/skills/debug-test-failures .github/skills/debug-test-failures && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .github/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/haste --skill debug-test-failures -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install microsoft/haste debug-test-failures --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.github/skills/debug-test-failures .opencode/skills/debug-test-failures && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "debug-test-failures" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/debug-test-failures into .opencode/skills/debug-test-failures/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "debug-test-failures", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
debug-test-failures- GitHub stars
- 106
- Token cost
- ~735 tokens
- SKILL.md length
- 347 words
- Files
- 1
- Skills in repo
- 9
- Repo updated
- First seen
- Licence
- MIT
At a glance
Systematic debugging workflow for test failures. An agent skill from microsoft/haste.
- Tests are failing
- SKILL.md covers Overview, Key Concepts, Patterns & Techniques and Decision Framework, plus 1 more section
- Calls npm
- A CI build is red
What it does
Debug Test Failures is an agent skill from microsoft/haste, published by the product's own GitHub organization. Systematic debugging workflow for test failures. Use when tests are failing, a CI build is red, or when asked to debug test issues.
Its SKILL.md is about 740 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Failing and flaky tests and Debugging. The repository describes itself as: High Speed Assessment and Satellite Tracking for Emergencies. The licence is MIT.
When your agent uses it
- Tests are failing
- A CI build is red
- Asked to debug test issues
Example prompts
- “/debug-test-failures”
Requirements
- Python 3
- Pre-approved tools (allowed-tools): shell
What it can do on your machine
Read from SKILL.md and the folder at commit 079bd89. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
shell
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
npm
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Debug Test Failures loads about 735 tokens when it runs. Until then it costs about 38 tokens; SKILL.md has 347 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from microsoft/haste at commit 079bd89, republished under its MIT licence (© microsoft). 347 words, ~735 tokens.
Download SKILL.mdSave it as
.claude/skills/debug-test-failures/SKILL.md (or your agent's skills folder).- name
- debug-test-failures
- description
- Systematic debugging workflow for test failures. Use when tests are failing, a CI build is red, or when asked to debug test issues.
- allowed-tools
- shell
- source
- Internal engineering practices
- domain
- testing
- level
- intermediate
- agents
- backend-dev, gis, ui, backend-validation
- created_date
- 2026-04-27
- status
- draft
Debug Test Failures
Overview
A systematic process for diagnosing and fixing test failures. Use this skill when tests fail, CI is red, or someone reports a broken build. The key principle: find the root cause, not just the symptom.
Key Concepts
Failure Categories
- Deterministic failure: Same result every time. Usually a code bug or outdated test.
- Flaky failure: Intermittent. Usually caused by timing, ordering, shared state, or external dependencies.
- Environment failure: Works locally, fails in CI. Usually paths, permissions, or missing dependencies.
Patterns & Techniques
Systematic Debugging Process
Step 1: Reproduce Run the failing test in isolation:
# Python tests
cd hastelib && hatch run test:pytest
# UI lint
cd ui && npm run lintRun it 2-3 times. If intermittent, it's likely flaky.
Step 2: Analyze
- Read the error message and stack trace carefully
- Identify the assertion that failed: expected vs actual values
- Check if the failure is in the test or the code under test
Step 3: Investigate
- Read the test code to understand what it's testing
- Read the production code being tested
- Check recent changes to both
- Common root causes:
- Changed function signatures or return types
- Modified data structures
- New dependencies not mocked
- Environment differences (paths, timezones, locale)
- Race conditions in async code
Step 4: Fix
- Fix the root cause, not just the symptom
- If the test is wrong (testing outdated behavior), update the test
- If the code is wrong, fix the code
- Run the full test suite:
cd hastelib && hatch run test:pytest
Step 5: Report Summarize: root cause, fix applied, verification that all tests pass.
Decision Framework
| Symptom | Likely Cause | Action |
|---|---|---|
| Test always fails | Code bug or outdated test | Read both, fix the wrong one |
| Test passes locally, fails in CI | Environment difference | Check paths, deps, permissions |
| Test fails intermittently | Timing, shared state, or ordering | Add isolation, remove shared state |
| Many tests fail at once | Breaking change in shared code | Find the common dependency |
Common Pitfalls
- Fixing the test to match broken code — Verify the code is correct before changing the test
- Adding sleep() to fix flaky tests — Fix the root cause (usually missing await or shared state)
- Only running the fixed test — Always run the full suite to check for regressions
© microsoft, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .github/skills/debug-test-failures of microsoft/haste.
Open the folder on GitHubat commit 079bd89
Compare with similar skills
Debug Test Failures next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Debug Test Failures this skillmicrosoft/haste | 106 | — | ~735 | Automated safety check: Pass | MIT | |
| Pester Failure AnalysisPowerShell/PowerShell | 56k | — | ~5.1k | Automated safety check: Pass | MIT | |
| Testingkortix-ai/suna | 20k | — | ~3.6k | Automated safety check: Notes | Custom licence | |
| OpenLogi Change VerificationAprilNEA/OpenLogi | 23k | — | ~1.4k | Automated safety check: Pass | Apache-2.0 | |
| RustPython Test Failure InvestigationRustPython/RustPython | 22k | — | ~467 | Automated safety check: Pass | MIT | |
| Issue To Regression Testbrunosabot/streamline-card | 269 | — | ~529 | Automated safety check: Pass | MIT |
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Related
Categories
Questions about Debug Test Failures
What does Debug Test Failures do?
Systematic debugging workflow for test failures. An agent skill from microsoft/haste. Debug Test Failures is an agent skill from microsoft/haste, published by the product's own GitHub organization. Systematic debugging workflow for test failures.
When should I use Debug Test Failures?
Debug Test Failures fits situations like: tests are failing; A CI build is red; asked to debug test issues.
How do I install Debug Test Failures in Claude Code?
Run `npx skills add microsoft/haste --skill debug-test-failures -a claude-code`. Or copy the skill folder (.github/skills/debug-test-failures in microsoft/haste) into .claude/skills/debug-test-failures in your project. Claude Code loads it when a task matches its description.
How do I install Debug Test Failures in Codex?
Run `npx skills add microsoft/haste --skill debug-test-failures -a codex`. Or copy the skill folder (.github/skills/debug-test-failures in microsoft/haste) into .agents/skills/debug-test-failures in your project. Codex loads it when a task matches its description.
Can I use Debug Test Failures in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add microsoft/haste --skill debug-test-failures -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/debug-test-failures, .gemini/skills/debug-test-failures, .github/skills/debug-test-failures and .opencode/skills/debug-test-failures in your project.
What does Debug Test Failures need to run?
Going by SKILL.md and its folder, Debug Test Failures needs the command-line tools its instructions call (npm). Our summary lists: Python 3. Its frontmatter pre-approves these tools: shell.
Does Debug Test Failures access the network?
SKILL.md contains no URLs. Its commands use npm, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Debug Test Failures safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Debug Test Failures use?
Debug Test Failures is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Debug Test Failures use?
About 735 tokens (SKILL.md is roughly 2.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Debug Test Failures?
Skills that share tags, products or a category with Debug Test Failures: Pester Failure Analysis (PowerShell/PowerShell, 56k stars), Testing (kortix-ai/suna, 20k stars), OpenLogi Change Verification (AprilNEA/OpenLogi, 23k stars) and RustPython Test Failure Investigation (RustPython/RustPython, 22k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Debug Test Failures?
microsoft (a GitHub organization, an official publisher) maintains it in microsoft/haste, which has 106 GitHub stars. The repository holds 9 skills in this directory. The repository was last updated on October 2, 2026.
Source: microsoft/haste on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.