CI Tests against nightly rust are failing

[alamb]

Describe the bug

The checks started failing here:
https://github.com/apache/arrow-rs/runs/4286145388?check_suite_focus=true

failures:

---- src/array/mod.rs - array (line 49) stdout ----
error[E0259]: the name `arrow` is defined multiple times
 --> src/array/mod.rs:50:1
  |
2 | extern crate arrow;
  | ------------------- previous import of the extern crate `arrow` here
3 | 
4 | extern crate r#arrow;
  | ^^^^^^^^^^^^^^^^^^^^^ `arrow` reimported here
  |
  = note: `arrow` must be defined only once in the type namespace of this module

error: aborting due to previous error

For more information about this error, try `rustc --explain E0259`.
Couldn't compile the test.
---- src/datatypes/schema.rs - datatypes::schema::Schema::new (line 55) stdout ----
error[E0259]: the name `arrow` is defined multiple times
 --> src/datatypes/schema.rs:55:1
  |
2 | extern crate arrow;
  | ------------------- previous import of the extern crate `arrow` here
3 | extern crate r#arrow;
  | ^^^^^^^^^^^^^^^^^^^^^ `arrow` reimported here
  |
  = note: `arrow` must be defined only once in the type namespace of this module

error: aborting due to previous error

For more information about this error, try `rustc --explain E0259`.
Couldn't compile the test.
---- src/datatypes/schema.rs - datatypes::schema::Schema::new_with_metadata (line 72) stdout ----
error[E0259]: the name `arrow` is defined multiple times
 --> src/datatypes/schema.rs:72:1
  |
2 | extern crate arrow;
  | ------------------- previous import of the extern crate `arrow` here
3 | extern crate r#arrow;
  | ^^^^^^^^^^^^^^^^^^^^^ `arrow` reimported here
  |
  = note: `arrow` must be defined only once in the type namespace of this module

error: aborting due to previous error

For more information about this error, try `rustc --explain E0259`.
Couldn't compile the test.

failures:
    src/array/mod.rs - array (line 49)
    src/datatypes/schema.rs - datatypes::schema::Schema::new (line 55)
    src/datatypes/schema.rs - datatypes::schema::Schema::new_with_metadata (line 72)

test result: FAILED. 128 passed; 3 failed; 0 ignored; 0 measured; 0 filtered out; finished in 135.22s

error: test failed, to rerun pass '--doc'
Error: Process completed with exit code 101.

To Reproduce
Run CI on nightly

Expected behavior
Tests should pass

[alamb]

Can reproduce (on linux only):

rustup update
cd arrow
cargo +nightly test  --features "simd" 

I am not sure what is going on re the windows failures...