D071 - A small inner filesystem is warned about, not adjusted

Status: decided Date: 2026-09-26

selfish pack warns when the inner filesystem is smaller than DEFAULT_CACHE_SIZE. The header's declared cache size stays the value every real package carries; Builder::cache_size overrides it for a caller that asks.

Why: the hardware refuses to mount an inner filesystem below a fixed size, somewhere in (720896, 1769472] bytes, with Failed to enable GDDR5 cache and EINVAL. Lowering the declared cache size to the inner size does not change that, so only the caller, by padding the title, can.

Rejected:

• Clamping the declared cache size: tested on hardware and refused identically.
• Refusing to build: a small title is not an error in the builder's input.