PDF Toolkit
XiaomiMiMo/MiMo-Code
Reads, transforms, composes and fills PDFs with Python scripts for extraction, merging, watermarking, encryption, OCR and form filling.
Debug Python PDF generation errors by using unbuffered output and stderr inspection to reveal actual tracebacks
Install PDF Debug Unbuffered
$ npx skills add HKUDS/OpenSpace --skill pdf-debug-unbuffered -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install HKUDS/OpenSpace pdf-debug-unbuffered --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/HKUDS/OpenSpace.git skills-src && mkdir -p .claude/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .claude/skills/pdf-debug-unbuffered && 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 "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .claude/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbufferedType 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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install HKUDS/OpenSpace pdf-debug-unbuffered --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HKUDS/OpenSpace.git skills-src && mkdir -p .agents/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .agents/skills/pdf-debug-unbuffered && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .agents/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install HKUDS/OpenSpace pdf-debug-unbuffered --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HKUDS/OpenSpace.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .cursor/skills/pdf-debug-unbuffered && 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 "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .cursor/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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/HKUDS/OpenSpace.git --path benchmarks/gdpval/skills/pdf-debug-unbuffered--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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install HKUDS/OpenSpace pdf-debug-unbuffered --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HKUDS/OpenSpace.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .gemini/skills/pdf-debug-unbuffered && 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 "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .gemini/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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 HKUDS/OpenSpace pdf-debug-unbufferedInstalls 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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/HKUDS/OpenSpace.git skills-src && mkdir -p .github/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .github/skills/pdf-debug-unbuffered && 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 "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .github/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install HKUDS/OpenSpace pdf-debug-unbuffered --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HKUDS/OpenSpace.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/benchmarks/gdpval/skills/pdf-debug-unbuffered .opencode/skills/pdf-debug-unbuffered && 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 "pdf-debug-unbuffered" agent skill from https://github.com/HKUDS/OpenSpace/tree/main/benchmarks/gdpval/skills/pdf-debug-unbuffered into .opencode/skills/pdf-debug-unbuffered/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pdf-debug-unbuffered", 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
pdf-debug-unbuffered- GitHub stars
- 7.7k
- Token cost
- ~754 tokens
- SKILL.md length
- 309 words
- Files
- 2
- Skills in repo
- 199
- Repo updated
- First seen
- Licence
- MIT
At a glance
Debug Python PDF generation errors by using unbuffered output and stderr inspection to reveal actual tracebacks
- Works in 5 steps: Identify the failing script → Run with unbuffered output → Analyze the traceback → …
- Tasks that involve PDF
- SKILL.md covers Core Technique, Why This Works, Step-by-Step Debugging and Common Issues Revealed, plus 3 more sections
- Calls python
What it does
PDF Debug Unbuffered is an agent skill from HKUDS/OpenSpace. Debug Python PDF generation errors by using unbuffered output and stderr inspection to reveal actual tracebacks
Its SKILL.md is about 750 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file.
It sits in Documents & Office, covering PDF and Debugging. It works with Python and pypdf. The repository describes itself as: "OpenSpace: The Skill Management Layer for AI Agents" -- https://open-space.cloud/. The licence is MIT.
When your agent uses it
- Tasks that involve PDF
- Tasks that involve Debugging
Example prompts
- “/pdf-debug-unbuffered”
Requirements
- Python 3
Workflow steps
5 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 3827781. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
python
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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
PDF Debug Unbuffered loads about 754 tokens when it runs. Until then it costs about 33 tokens; SKILL.md has 309 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 HKUDS/OpenSpace at commit 3827781, republished under its MIT licence (© HKUDS). 309 words, ~754 tokens.
Download SKILL.mdSave it as
.claude/skills/pdf-debug-unbuffered/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- pdf-debug-unbuffered
- description
- Debug Python PDF generation errors by using unbuffered output and stderr inspection to reveal actual tracebacks
PDF Generation Debug Technique
When Python PDF libraries (reportlab, fpdf, etc.) fail with generic "unknown error" messages, the actual cause is often hidden due to output buffering or error swallowing. This skill provides a technique to expose the real traceback.
Core Technique
Run the Python script with the -u flag (unbuffered output) and pipe stderr through head to capture the actual error:
python -u your_script.py 2>&1 | head -100Or more specifically, to focus on stderr:
python -u your_script.py 2>&1 | head -50Why This Works
-uflag: Forces Python to run in unbuffered mode, ensuring output (including errors) is flushed immediately rather than held in buffers that may be lost on crash2>&1: Redirects stderr to stdout so both streams are captured togetherhead: Limits output to show the most relevant error messages at the top
Step-by-Step Debugging
Step 1: Identify the failing script
Locate the Python script that generates the PDF and is producing generic errors.
Step 2: Run with unbuffered output
python -u generate_pdf.py 2>&1 | head -100Step 3: Analyze the traceback
Look for:
- Import errors (missing dependencies)
- File path issues (invalid paths, permission errors)
- Font registration problems (common with reportlab)
- Memory or resource constraints
Step 4: Fix the underlying issue
Address the specific error revealed in the traceback.
Step 5: Re-run normally
Once fixed, run the script without the debug flags to confirm it works:
python generate_pdf.pyCommon Issues Revealed
| Symptom | Likely Cause |
|---|---|
| "unknown error" on PDF save | File path doesn't exist or no write permissions |
| Generic failure during build | Missing font files or font registration issues |
| Silent crash | ImportError for missing dependencies |
| Incomplete PDF | Script terminated early due to unhandled exception |
Alternative Approaches
If the above doesn't work, try:
# Capture full stderr to a file
python -u script.py 2> error.log
# Use Python's traceback module explicitly
python -c "import traceback; exec(open('script.py').read())" 2>&1
# Run with verbose import tracing
python -v -u script.py 2>&1 | head -200Example: Debugging reportlab
# Before: Generic error
python create_checklist.py
# Output: "Error: unknown"
# After: Actual traceback
python -u create_checklist.py 2>&1 | head -50
# Output: "FileNotFoundError: [Errno 2] No such file or directory: '/fonts/Helvetica.ttf'"Notes
- This technique applies to any Python script with opaque error messages, not just PDF generation
- The
-uflag is available in Python 2.7+ and all Python 3 versions - For production debugging, consider logging to a file instead of using
head
© HKUDS, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file in benchmarks/gdpval/skills/pdf-debug-unbuffered of HKUDS/OpenSpace.
- SKILL.md
- .skill_id
Open the folder on GitHubat commit 3827781
Compare with similar skills
PDF Debug Unbuffered 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 |
|---|---|---|---|---|---|---|
| PDF Debug Unbuffered this skillHKUDS/OpenSpace | 7.7k | — | ~754 | Automated safety check: Pass | MIT | |
| PDF ToolkitXiaomiMiMo/MiMo-Code | 14k | — | ~1.7k | Automated safety check: Pass | Apache-2.0 | |
| PDF Generation, Forms and Extractionpipeshub-ai/pipeshub-ai | 3.8k | — | ~2.9k | Automated safety check: Pass | Apache-2.0 | |
| PDFNousResearch/hermes-agent | 252k | — | ~3.1k | Automated safety check: Pass | MIT | |
| PDF ExploreHughYau/AcademicForge | 2.6k | — | ~3.1k | Automated safety check: Pass | Apache-2.0 | |
| PDF Readerespennilsen/pi | 122 | — | ~1.6k | Automated safety check: Pass | MIT |
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Related
Categories
Questions about PDF Debug Unbuffered
What does PDF Debug Unbuffered do?
Debug Python PDF generation errors by using unbuffered output and stderr inspection to reveal actual tracebacks. PDF Debug Unbuffered is an agent skill from HKUDS/OpenSpace.
When should I use PDF Debug Unbuffered?
PDF Debug Unbuffered fits situations like: tasks that involve PDF; tasks that involve Debugging.
How do I install PDF Debug Unbuffered in Claude Code?
Run `npx skills add HKUDS/OpenSpace --skill pdf-debug-unbuffered -a claude-code`. Or copy the skill folder (benchmarks/gdpval/skills/pdf-debug-unbuffered in HKUDS/OpenSpace) into .claude/skills/pdf-debug-unbuffered in your project. Claude Code loads it when a task matches its description.
How do I install PDF Debug Unbuffered in Codex?
Run `npx skills add HKUDS/OpenSpace --skill pdf-debug-unbuffered -a codex`. Or copy the skill folder (benchmarks/gdpval/skills/pdf-debug-unbuffered in HKUDS/OpenSpace) into .agents/skills/pdf-debug-unbuffered in your project. Codex loads it when a task matches its description.
Can I use PDF Debug Unbuffered 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 HKUDS/OpenSpace --skill pdf-debug-unbuffered -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/pdf-debug-unbuffered, .gemini/skills/pdf-debug-unbuffered, .github/skills/pdf-debug-unbuffered and .opencode/skills/pdf-debug-unbuffered in your project.
What does PDF Debug Unbuffered need to run?
Going by SKILL.md and its folder, PDF Debug Unbuffered needs the command-line tools its instructions call (python). Our summary lists: Python 3.
Does PDF Debug Unbuffered access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is PDF Debug Unbuffered 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 PDF Debug Unbuffered use?
PDF Debug Unbuffered 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 PDF Debug Unbuffered use?
About 754 tokens (SKILL.md is roughly 3k 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 PDF Debug Unbuffered?
Skills that share tags, products or a category with PDF Debug Unbuffered: PDF Toolkit (XiaomiMiMo/MiMo-Code, 14k stars), PDF Generation, Forms and Extraction (pipeshub-ai/pipeshub-ai, 3.8k stars), PDF (NousResearch/hermes-agent, 252k stars) and PDF Explore (HughYau/AcademicForge, 2.6k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains PDF Debug Unbuffered?
HKUDS (a GitHub organization) maintains it in HKUDS/OpenSpace, which has 7,743 GitHub stars. The repository holds 199 skills in this directory. The repository was last updated on August 12, 2026.
Source: HKUDS/OpenSpace on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.