body::to_bytes doctest fails with default feature set

[whentze]

Version

Current git master aka 8062714

Platform

Linux 5.14.0-4-amd64 #1 SMP Debian 5.14.16-1 (2021-11-03) x86_64 GNU/Linux

Description

I cloned the repo in order to hack on the code, and I started out by making sure I could run the tests.
That is, I did:

git clone https://github.com/hyperium/hyper
cd hyper
cargo test

However, one of the doctests fails to compile:

   Doc-tests hyper

running 6 tests
test src/ext.rs - ext::HeaderCaseMap (line 14) ... ignored
test src/ext.rs - ext::HeaderCaseMap (line 22) ... ignored
test src/body/to_bytes.rs - body::to_bytes::to_bytes (line 19) ... FAILED
test src/service/make.rs - service::make::make_service_fn (line 106) ... ok
test src/service/util.rs - service::util::service_fn (line 13) ... ok
test src/body/body.rs - body::body::Body::empty (line 123) ... ok

failures:

---- src/body/to_bytes.rs - body::to_bytes::to_bytes (line 19) stdout ----
error[E0433]: failed to resolve: could not find `Client` in `hyper`
  --> src/body/to_bytes.rs:28:21
   |
12 | let client = hyper::Client::new();
   |                     ^^^^^^ could not find `Client` in `hyper`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0433`.
Couldn't compile the test.

failures:
    src/body/to_bytes.rs - body::to_bytes::to_bytes (line 19)

test result: FAILED. 3 passed; 1 failed; 2 ignored; 0 measured; 0 filtered out; finished in 0.27s

It looks like the test depends on some feature(s) outside of the default set.
I successfully fixed the issue locally by adding a #[cfg(...)] guard to the test, but I'm not sure if the real bug is in fact that the test depends on extra features.

Also, there seems to be a CI job that runs the test against many feature sets. For some reason it did not catch this. Maybe I'm looking at the wrong thing, or the job is buggy, or it's just really bad luck. In any case, might be worth investigating.