CI Fail on cargo doctest

[metesynnada]

Describe the bug

Latest CI fails all have a common test failure.

failures:

---- src/lib.rs - user_guid_example_tests (line 493) stdout ----
error[E0433]: failed to resolve: use of undeclared crate or module `snmalloc_rs`
 --> src/lib.rs:497:15
  |
6 | static ALLOC: snmalloc_rs::SnMalloc = snmalloc_rs::SnMalloc;
  |               ^^^^^^^^^^^ use of undeclared crate or module `snmalloc_rs`

error[E0433]: failed to resolve: use of undeclared crate or module `snmalloc_rs`
 --> src/lib.rs:497:39
  |
6 | static ALLOC: snmalloc_rs::SnMalloc = snmalloc_rs::SnMalloc;
  |                                       ^^^^^^^^^^^ use of undeclared crate or module `snmalloc_rs`

error[E0752]: `main` function is not allowed to be `async`
 --> src/lib.rs:499:1
  |
8 | async fn main() -> datafusion::error::Result<()> {
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `main` function is not allowed to be `async`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0433, E0752.
For more information about an error, try `rustc --explain E0433`.
Couldn't compile the test.
---- src/lib.rs - user_guid_example_tests (line 513) stdout ----
error: character literal may only contain one codepoint
 --> src/lib.rs:514:11
  |
3 | RUSTFLAGS='-C target-cpu=native' cargo +nightly run --release
  |           ^^^^^^^^^^^^^^^^^^^^^^
  |
help: if you meant to write a `str` literal, use double quotes
  |
3 | RUSTFLAGS="-C target-cpu=native" cargo +nightly run --release
  |           ~~~~~~~~~~~~~~~~~~~~~~

error: expected one of `.`, `;`, `?`, `}`, or an operator, found `cargo`
 --> src/lib.rs:514:34
  |
3 | RUSTFLAGS='-C target-cpu=native' cargo +nightly run --release
  |                                  ^^^^^ expected one of `.`, `;`, `?`, `}`, or an operator

error: aborting due to 2 previous errors

Couldn't compile the test.

failures:
    src/lib.rs - user_guid_example_tests (line 493)
    src/lib.rs - user_guid_example_tests (line 513)

test result: FAILED. 57 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out; finished in 458.46s

To Reproduce

No response

Expected behavior

Check pass.

Additional context

No response

[waynexia]

One failure CI job is https://github.com/apache/arrow-datafusion/actions/runs/4685079004/jobs/8301949150 from #5962. It looks like #5989 has fixed this.

I've tried the latest HEAD on my machine and it works fine:

❯ cargo test --doc --workspace user_guid_example_tests 
   Compiling substrait v0.7.3
   Compiling datafusion-substrait v22.0.0 (/home/wayne/repo/arrow-datafusion/datafusion/substrait)
    Finished test [unoptimized + debuginfo] target(s) in 2.35s
   Doc-tests datafusion

running 5 tests
test src/lib.rs - user_guid_example_tests (line 493) ... ignored
test src/lib.rs - user_guid_example_tests (line 350) ... ok
test src/lib.rs - user_guid_example_tests (line 370) ... ok
test src/lib.rs - user_guid_example_tests (line 427) ... ok
test src/lib.rs - user_guid_example_tests (line 407) ... ok

[metesynnada]

I think it is fixed.