Your point is totally fair for evaluating security tooling. A few notes -
1. I implemented this in Bash to avoid having an opaque binary in the way.
2. All sandbox-exec profiles are split up into individual files by specific agent/integration, and are easily auditable (https://github.com/eugene1g/agent-safehouse/tree/main/profil...)
3. There are E2E tests validating sandboxing behavior under real agents
4. You don't even need the Safehouse Bash wrapper, and can use the Policy Builder to generate a static policy file with minimal permissions that you can feed to sandbox-exec directly (https://agent-safehouse.dev/policy-builder). Or feed the repo to your LLMs and have them write your own policy from the many examples.
5. This whole repo should be a StrongDM-style readme to copy&paste to your clanker. I might just do that "refactor", but for now added LLM instructions to create your own sandbox-exec profiles https://agent-safehouse.dev/llm-instructions.txt
Would xcodebuild work in this context? Presumably I'd watch a log (or have an agent) and add permissions until it works?
Yes, Safehouse should work for xcodebuild workloads in the way you described - try to run it, watch for failures, extend the profile, try again. Your agent can do this in a loop by itself - just feed it the repo as there are many integrations that are not enabled by default that will help it.