I also don't like subagents.

I usually have my main agent write a wrapper command around things like that as it hits them. The wrapper only surfaces the important info, writes the full log to a file, and the agent gets some instructions on using sed and the like to navigate the output.

It seems to work reasonably well.

>When cargo fails to build and creates a massive amount of compile errors, you're better off having this preprocess step.

Claude already greps and tails every output by itself, a sub-agent would do the same.