offline
If my development environment needs the internet to work, that's a dependency bug.
The network is the least reliable resource I have. Keep it out of the critical path.
I test this by turning Wi-Fi off.
If the build fails, or the tests stop, or the docs disappear, something still lives outside the machine. That's the thing to fix.
A good development loop works offline. cargo build builds. cargo test tests. cargo doc --open opens the docs. The binary runs. The help text works. The man page is there.
When it works, I can build, test, and run the software without asking anyone. That's the goal.
The opposite is online by default. The editor talks to a server. Some tool wants an API key. The build downloads something. The docs live behind a request. Before writing code, I'm already waiting on someone else's uptime.
Run the unplugged test. Mine passed. I still couldn't debug.