Reddit Field Test: MiMo-V2.6-Pro Gets Stuck in a grep Infinite Loop During a UI/UX Terminal Modification Task

One-sentence conclusion

In a real website UI/UX modification task, the poster said that both MiMo-V2.6-Pro and MiMo-V2.6-Flash triggered a grep-related infinite loop in the terminal and failed to fix the code after approximately 30 minutes; when the same modification was assigned to DeepSeek V4.1 Flash, it continued as expected and output a complete terminal work history.

Suitable use cases

• Suitable tasks: This material only shows that frontend maintenance tasks requiring terminal tool calls, code changes, and observable execution can carry a risk of failure; it cannot establish that the model is suitable or unsuitable for all coding tasks.

• Unsuitable tasks: It cannot be used to assess benchmark scores, price, speed, code quality, or long-horizon Agent capability, and it cannot replace a controlled retest.

• Applicable model version: The original post explicitly names Mimo v2.6 Pro; it also tests Mimo v2.6 Flash, and the two must be kept separate. The post does not mention MiMo-V2.6-Pro-RL or Ultraspeed.

• Applicable client, Agent, or API: The body explicitly mentions only a terminal and a website UI/UX modification; it does not disclose the specific client, Agent, provider, or API.

• Recommended reasoning level and parameters: Not disclosed and cannot be inferred.

Test method

1. The poster requested a UI/UX update for a website they were operating.

2. The same modification task was assigned separately to MiMo v2.6 Flash and MiMo v2.6 Pro.

3. The poster observed the execution process in the terminal and reported that both models entered a grep-related infinite loop after making some progress.

4. After waiting approximately 30 minutes, the poster still could not confirm that the task was progressing, and the code had not been fixed.

5. The same modification task was assigned to DeepSeek V4.1 Flash as a comparison; the poster said it progressed as expected and output the complete work history to the terminal.

Original evidence and data

• Task: Update the UI/UX of a website in operation.

• Model samples: MiMo v2.6 Flash and MiMo v2.6 Pro; the comparison model was DeepSeek V4.1 Flash.

• Tool/environment: Terminal; the specific Agent, provider, operating system, repository, tool version, and parameters were not disclosed.

• Observed failure: After making some progress, both MiMo versions entered a grep-related infinite loop; no code was fixed after approximately 30 minutes.

• Comparison result: The poster said DeepSeek V4.1 Flash faithfully executed the same modification and output the complete work history to the terminal.

• Visible artifacts: The original post provides no code diff, execution log, screenshot, repository link, or downloadable build artifact; “output the complete work history” is the poster's description, and the page does not display that log.

• Public sample size: 1 UI/UX modification task from the same poster, attempted with multiple models; this is not a controlled benchmark.

Scope and limitations

• This is one user's account of one frontend maintenance task and cannot be generalized into a conclusion about MiMo-V2.6-Pro's overall capability.

• The original post does not disclose the complete prompt, codebase, reproduction steps, provider, model parameters, tool version, or logs, so the “grep infinite loop” cannot be reproduced.

• The behavior of MiMo-V2.6-Flash is recorded separately from MiMo-V2.6-Pro; this piece's core conclusion covers only the post's direct description of Pro.

• DeepSeek V4.1 Flash's success is also the same user's comparison observation and should not be treated as an independent evaluation result.

Source excerpts or observations (short excerpts for compliance only)

“an infinite loop related to grep started occurring in the terminal.”

“for 30 minutes no code was fixed.”

“DS 4.1 Flash is still much better..”