Asking agent to run a CLI command that does a lot of shell "magic" is really slow

[kevmoo]

What happened?

1. ask agent to run dart run ~/github/dartdoc/bin/dartdoc.dart --output $(mktemp -d)
2. The CLI has some "spinning" elements and other UX magic for progress
3. It was 100x slower than running it on the CLI

What did you expect to happen?

1. To be ~as fast as running it normally

Client information

Client Information

Run gemini to enter the interactive CLI, then run the /about command.

│ About Gemini CLI                                                                                                       │ CLI Version                              0.28.2                                                                        │ Git Commit                               da5e47ae3                                                                     │ Model                                    auto-gemini-3                                                                 │ Sandbox                                  no sandbox                                                                    │ OS                                       darwin                                                                        ```

</details>

### Login information

API key (I think)

### Anything else we need to know?

My hunch is that all of the raw bytes of the terminal animation silly are being processed by gemini and that's why it's so slow...but just a hunch

[kevmoo]

To confirm my suspicion, I used dart run ~/github/dartdoc/bin/dartdoc.dart --output $(mktemp -d) --json – which does NOT do any busy output in the terminal and it ran fast!

[jacob314]

I also see this when find . runs much faster on the command line than in the CLI. We should examine how we are integrating terminal rendering to ensure we aren't missing some simple optimizations.
Fyi @galz10

[jacob314]

Before repro streaming a 5GB file with easy to read file locations
https://screencast.googleplex.com/cast/NTE1NTk3NTcyMjk1ODg0OHxkMjE4ODdjNy0xYg