Local-Works / Production-Breaks Lab

This lab is built around the most misleading deployment sentence in web development:

But it works on my computer.

Good.

Now prove what is different.

Incident 1: base path

Create or use a disposable link that assumes root deployment.

Local preview works.

Production/repository-subpath model fails.

Diagnose from generated href + public URL.

Incident 2: plugin/build environment

Use a bounded plugin or dependency difference scenario.

Local bundle builds.

Hosted build does not support/resolve the same extension path.

Compare:

• Gemfile/lock;
• local version;
• Pages workflow/environment;
• official current support.

Incident 3: case-sensitive asset path

Create a case mismatch if your development filesystem permits it to appear locally.

Observe production behavior or reason from a controlled environment that exposes the mismatch.

Incident 4: production-only condition

Create a harmless jekyll.environment marker or other controlled conditional.

Verify it differs only where expected.

Incident report

For each:

Local evidence:
Production evidence:
Difference between environments:
Root cause:
Source repair:
Redeployment evidence:

Checkpoint

The point is not to memorize four fixes.

The point is to compare two environments until the changed assumption becomes visible.