21_Final_Rules_of_Survival.md

The Only Rules That Actually Matter

Purpose of This Final Chapter

This chapter exists to end the guide.

No new tools.
No new commands.
No new workflows.

Only the rules that keep OpenLane alive.

If you remember nothing else, remember this chapter.

The Fundamental Truth

OpenLane is not fragile.

Your environment management is.

Almost every “OpenLane problem” is actually one of the following:

• Version drift
• Environment mutation
• Asset rebuild
• Toolchain mixing
• Unrecoverable updates

These are not bugs.
They are self-inflicted wounds.

Rule 1 — Your Environment Is an Asset

Treat your OpenLane environment as:

• A compiled binary
• A golden image
• A frozen artifact

Not as:

• A playground
• A rolling-release system
• A development sandbox

Once it works, its value is in staying unchanged.

Rule 2 — Never Fix a Broken Environment

If something breaks:

❌ Do not debug first
❌ Do not update packages
❌ Do not rerun installers

✔ Export / import immediately

Debugging happens after preservation, never before.

Rule 3 — Updates Require Cloning, Not Courage

Want to try:

• A new OpenLane version
• A new PDK
• A new Docker version
• A new OS update

The correct process is always:

Working environment
        ↓ clone
Experimental environment (allowed to die)

Never experiment on your only working system.

Rule 4 — Rebuilding Is Failure

If you hear yourself saying:

• “I’ll just rebuild it”
• “It’s faster to reinstall”
• “I know how to set it up now”

You have already lost.

A reproducible environment is one that never needs rebuilding.

Rule 5 — Separation Is Non-Negotiable

These must never touch each other:

• OpenLane1 ↔ OpenLane2
• Production ↔ Evaluation
• Stable ↔ Experimental
• Verified ↔ Unverified

Isolation is not optional. It is the price of reliability.

Rule 6 — GLS Without SDF Is a Lie

If timing matters:

• STA tells you where
• SDF GLS tells you what actually happens

Ignoring SDF GLS means accepting functional failure as “mystery”.

Waveforms are not decoration.
They are evidence.

Rule 7 — If It Ever Worked, It Can Work Again

Once you have:

• A passing make test
• A generated GDS
• A clean GLS run

That state is immortal as long as you exported it.

Hardware dies.
OS installs die.
People make mistakes.

Your environment does not — if you preserved it.

What This Repository Ultimately Teaches

Not OpenLane commands.

Not PDK internals.

Not STA theory.

It teaches discipline:

• Discipline to stop changing things
• Discipline to roll back instead of fixing
• Discipline to value stability over novelty

Final Checklist (Memorize This)

• Environment works → export
• Something breaks → import
• Want changes → clone
• Unsure → do nothing

This is enough.

Closing Statement

If OpenLane keeps breaking for you, it is not because OpenLane is unstable.

It is because you allowed instability in.

This guide removes that option.

Environment failures are optional.
You now know how to opt out.