git diagnose

Newer than bugreport. More artifacts.

🎯 What & why

git diagnose bundles a zip archive of repo diagnostics: object counts, packed-refs sizes, alternates, hooks, config. It is the modern successor to git bugreport for when you need to hand evidence to upstream maintainers.

🧠 Mental model

Think 'support bundle' for a Git repo: one zip with everything a maintainer needs to see what your repo looks like, without you having to ship the whole thing.

🛠️ Synopsis

git diagnose [-o <output-directory>] [-s <suffix>]
                  [--mode=(stats|all)]

🎚️ Switches & options

Flag	What it does
`-o, --output-directory <dir>`	Where to drop the zip (default: current dir)
`-s, --suffix <suffix>`	Custom filename suffix (replaces the default timestamp)
`--mode=stats`	Default: counts, sizes, config, hooks list - no object payloads
`--mode=all`	⚠️ Includes packed-refs and reachable-pack contents - can leak data

💡 Use cases

Filing a bug against git itself or a hosted forge
Diagnosing a slow or bloated repository
Sharing repo shape with a colleague without sharing the code
Auditing what hooks and config a cloned repo carries

🧪 Examples

Default stats dump

git diagnose

Drop into /tmp

git diagnose -o /tmp

Custom suffix

git diagnose -s broken-fetch-2026

Full mode (careful)

git diagnose --mode=all -o /tmp

🎓 Recommendations

Run before opening a bug upstream - maintainers will ask for it.
Use --mode=stats unless they specifically ask for all; stats is privacy-safe.
Inspect the zip before sending. You own what is inside it.

🪤 Common pitfalls

--mode=all can include reachable refs and pack data - do not blindly attach to public issues.
It runs in the current repo only - submodules need their own dump.
Older Git versions ship git bugreport instead; check git --version if diagnose is missing.

🔗 Related modules

📝 Quiz

Hit each option, then Check answers. Score is recorded; Next is always open.