Unable to build with no default features?

[ValuedMammal]

cargo build --no-default-features gave me a compile error. It seems that a FloatExt is not in scope.

error[E0599]: no method named `ceil` found for type `f32` in the current scope
  --> src/feerate.rs:86:35
   |
86 |         ((tx_weight as f32 / 4.0).ceil() * self.as_sat_vb()).ceil() as u64
   |                                   ^^^^ method not found in `f32`
   |
  ::: src/float.rs:67:8
   |
67 |     fn ceil(self) -> Self;
   |        ---- the method is available for `f32` here
   |
   = help: items from traits can only be used if the trait is in scope
help: trait `FloatExt` which provides `ceil` is implemented but not in scope; perhaps you want to import it
   |
 1 + use crate::float::FloatExt;