Fix "actor still initializing when getHandler() called" with containers. #3673
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jasnell
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Mar 9, 2025
We observed this error in production when testing containers. This change was technically composed by Claude Code. Transcript: https://claude-workerd-transcript.pages.dev/ensure-constructed Claude was surprisingly quick to narrow down where the problem might be, given just the error message. However, ultimately it needed hints to figure out the actual problem, and the code it initially proposed as the fix was not very good (though its choice to use `KJ_ON_SCOPE_FAILURE` was interesting!). The code in this commit may have been written by it, but only after very explicit prompting from me on what to do. I think I would have found and fixed the problem more quickly without Claude, but its ability to reason about the code is nevertheless impressive.
This was pre-existing (before the containers changes). I'm not sure if it would have been possible to trigger in practice, I noticed just from looking at the code.
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We observed this error in production when testing containers.
This change was technically composed by Claude Code. Transcript: https://claude-workerd-transcript.pages.dev/ensure-constructed
Claude was surprisingly quick to narrow down where the problem might be, given just the error message.
However, ultimately it needed hints to figure out the actual problem, and the code it initially proposed as the fix was not very good (though its choice to use
KJ_ON_SCOPE_FAILUREwas interesting!).The code in this commit may have been written by it, but only after very explicit prompting from me on what to do.
I think I would have found and fixed the problem more quickly without Claude, but its ability to reason about the code is nevertheless impressive.