Constant WPROF_PB_MIN_BYTES 

pub const WPROF_PB_MIN_BYTES: usize = 4096;

Minimum wprof .pb file size in bytes. wprof’s init_pb_trace emits a ~4 KB interned-string table (CAT + NAME + ANNK + ANNV ranges, ~216 entries × ~20 bytes wire cost) on every capture regardless of trace activity. A smaller file means wprof either aborted before init_pb_trace OR the .pb write/transport truncated.