`datafusion-proto` crate feature `json` is broken

[alamb]

Describe the bug

I am not sure what the json feature is supposed to do in datafusion-proto but it is broken

To Reproduce

cargo check --profile ci --all-targets --no-default-features -p datafusion-proto --features=json

Results in pages of errors like this

error[E0277]: the trait bound `datafusion_proto_common::Schema: Serialize` is not satisfied
    --> datafusion/proto/src/generated/pbjson.rs:159:55
     |
159  |             struct_ser.serialize_field("inputSchema", v)?;
     |                        ---------------                ^ the trait `Serialize` is not implemented for `datafusion_proto_common::Schema`
     |                        |
     |                        required by a bound introduced by this call
     |
     = note: for local types consider adding `#[derive(serde::Serialize)]` to your `datafusion_proto_common::Schema` type
     = note: for types from other crates check whether the crate offers a `serde` feature flag
     = help: the following other types implement trait `Serialize`:
               &'a T
               &'a mut T
               ()
               (T,)
               (T0, T1)
               (T0, T1, T2)
               (T0, T1, T2, T3)
               (T0, T1, T2, T3, T4)
             and 303 others
note: required by a bound in `serde::ser::SerializeStruct::serialize_field`
    --> /usr/local/cargo/registry/src/index.crates.io-1949cf8c6b5b557f/serde-1.0.218/src/ser/mod.rs:18[66](https://github.com/apache/datafusion/actions/runs/13788882508/job/38563713616?pr=15156#step:6:67):21
     |
1864 |     fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
     |        --------------- required by a bound in this associated function
1865 |     where
1866 |         T: ?Sized + Serialize;
     |                     ^^^^^^^^^ required by this bound in `SerializeStruct::serialize_field`

error[E0277]: the trait bound `datafusion_proto_common::Schema: Deserialize<'_>` is not satisfied
    --> datafusion/proto/src/generated/pbjson.rs:320:51
     |
320  | ...                   input_schema__ = map_.next_value()?;
     |                                             ^^^^^^^^^^ the trait `Deserialize<'_>` is not implemented for `datafusion_proto_common::Schema`
     |
     = note: for local types consider adding `#[derive(serde::Deserialize)]` to your `datafusion_proto_common::Schema` type
     = note: for types from other crates check whether the crate offers a `serde` feature flag
     = help: the following other types implement trait `Deserialize<'de>`:
               &'a [u8]
               &'a std::path::Path
               &'a str
               ()
               (T,)
               (T0, T1)
               (T0, T1, T2)
               (T0, T1, T2, T3)
             and 4[80](https://github.com/apache/datafusion/actions/runs/13788882508/job/38563713616?pr=15156#step:6:81) others
     = note: required for `std::option::Option<datafusion_proto_common::Schema>` to implement `Deserialize<'de>`
note: required by a bound in `next_value`

See more here https://github.com/apache/datafusion/actions/runs/13788882508/job/38563713616?pr=15156

Expected behavior

I expect the feature to work, or to be removed

Additional context

Found while working on

• Improved CI test coverage for rust features #15155
• Split out datafusion-substrait and datafusion-proto CI feature checks, increase coverage #15156

[timsaucer]

Recommend adding to this issue that we will want to re-enable the Check datafusion-proto (json) as part of closing the issue

[timsaucer]

Deleting comments that appear to be from an AI model.

[Shreyaskr1409]

https://github.com/apache/datafusion/pull/15185/files#r1991797793
#15089 (comment)

@irenjj maybe it is due to this issue, we are facing problems with JsonSink #15089 , as I said in one of my comments, no matter what I did, JsonSink is not getting used whereas CsvSink and others do get used. Maybe we can look into that issue after this issue is solved.

[irenjj]

https://github.com/apache/datafusion/pull/15185/files#r1991797793 #15089 (comment)

@irenjj maybe it is due to this issue, we are facing problems with JsonSink #15089 , as I said in one of my comments, no matter what I did, JsonSink is not getting used whereas CsvSink and others do get used. Maybe we can look into that issue after this issue is solved.

Thanks @Shreyaskr1409 , explain works in #15185(even though I wasn't able to construct a non-empty file_group case), I'd like to try to add more tests after this issue resolved.