The precompiled implementation is the only supported way to use the macros that are published in serde_derive
That statement is straight up gaslighting.
The precompiled binary is only provided for one platform; Windows, for example, does not use a precompiled binary but compiles its own from the source. How can he claim it’s the “only supported way”, when for most platforms he is doing it another way? Also, the crate, though most of its life, has been doing it another way.