compile errors when adding 15.0.0 as dependency

[syphar]

Trying to upgrade crates-index-diff on docs.rs I got some compile errors:

error[E0425]: cannot find function `serialize` in crate `hex`
   --> /Users/syphar/.cargo/registry/src/github.202132.xyz-1ecc6299db9ec823/crates-index-diff-15.0.0/src/types.rs:125:26
    |
125 | #[derive(Default, Clone, serde::Serialize, serde::Deserialize, Eq, PartialEq, Debug)]
    |                          ^^^^^^^^^^^^^^^^ not found in `hex`
    |
    = note: this error originates in the derive macro `serde::Serialize` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `SmartString<LazyCompact>: Serialize` is not satisfied
    --> /Users/syphar/.cargo/registry/src/github.202132.xyz-1ecc6299db9ec823/crates-index-diff-15.0.0/src/types.rs:125:26
     |
125  | #[derive(Default, Clone, serde::Serialize, serde::Deserialize, Eq, PartialEq, Debug)]
     |                          ^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `SmartString<LazyCompact>`
126  | pub struct CrateVersion {
127  |     /// The crate name, i.e. `clap`.
     |     -------------------------------- required by a bound introduced by this call
     |
     = help: the following other types implement trait `Serialize`:
               &'a T
               &'a mut T
               ()
               (T0, T1)
               (T0, T1, T2)
               (T0, T1, T2, T3)
               (T0, T1, T2, T3, T4)
               (T0, T1, T2, T3, T4, T5)
             and 131 others
note: required by a bound in `types::_::_serde::ser::SerializeStruct::serialize_field`
    --> /Users/syphar/.cargo/registry/src/github.202132.xyz-1ecc6299db9ec823/serde-1.0.147/src/ser/mod.rs:1899:12
     |
1899 |         T: Serialize;
     |            ^^^^^^^^^ required by this bound in `types::_::_serde::ser::SerializeStruct::serialize_field`

and some similar errors.

how to reproduce:

in an empty directory:

• cargo init
• cargo add crates-index-diff
• cargo build

related links

• rust-lang/docs.rs@master...syphar:docs.rs:upgrade-git
• https://github.com/syphar/docs.rs/actions/runs/3546296822/jobs/5955192211

[Byron]

Thanks for letting me know!

This is a very strange issue that I don't understand, and it also frightens me to see this happen as something like this could happen in any other project as well.

The question at the core of this is: How is it possible that the serde features of the hex and smartstring crates is active in builds done locally, but isn't active when crates-index-diff is used as dependency? Note that this is also the case when it's added with git add --path ...

Anyway, it's fixed now with the 15.0.1 release.