⚠ builder: return error when multiple reconcilers are set

[sbueringer]

Just saw this and was confused why we would want this behavior. I also looked at #1021 but I don't understand the reasoning.

If we want a silent overwrite behavior I would have expected Build/Complete to overwrite the reconciler from the previous set ctrlOptions not the other way around

I think this implementation still covers the original ask, folks can pass in a nil reconciler to Build/Complete

[FillZpp]

Sounds good, but not sure if someones have already relied on the behavior that c-r will use the reconciler in options first with no error?

[sbueringer]

Sounds good, but not sure if someones have already relied on the behavior that c-r will use the reconciler in options first with no error?

I would assume that if they do they would get an error now and then can decide which reconciler they want to use. If they want to keep using the one from options it should be trivial to pass in "nil" into Build/Complete

[k8s-ci-robot]

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