Why does DataFusion throw a Tokio 0.2 runtime error?

[alamb]

Note: migrated from original JIRA: https://issues.apache.org/jira/browse/ARROW-11578

thread 'tests::simple_join' panicked at 'must be called from the context of a Tokio 0.2.x runtime configured with either basic_scheduler or threaded_scheduler'.

{code:Rust}
#[tokio::test]
async fn simple_join() -> Result<()> {
let schema1 = Arc::new(Schema::new(vec![
Field::new("a", DataType::Utf8, false),
Field::new("b", DataType::Int32, false),
]));
let schema2 = Arc::new(Schema::new(vec![
Field::new("c", DataType::Utf8, false),
Field::new("d", DataType::Int32, false),
]));

    // define data.
    let batch1 = RecordBatch::try_new(
        schema1.clone(),
        vec![
            Arc::new(StringArray::from(vec!["a", "b", "c", "d"])),
            Arc::new(Int32Array::from(vec![1, 10, 10, 100])),
        ],
    )?;
    // define data.
    let batch2 = RecordBatch::try_new(
        schema2.clone(),
        vec![
            Arc::new(StringArray::from(vec!["a", "b", "c", "d"])),
            Arc::new(Int32Array::from(vec![1, 10, 10, 100])),
        ],
    )?;

    let mut ctx = ExecutionContext::new();

    let table1 = MemTable::try_new(schema1, vec![vec![batch1]])?;
    let table2 = MemTable::try_new(schema2, vec![vec![batch2]])?;

    ctx.register_table("t1", Box::new(table1));
    ctx.register_table("t2", Box::new(table2));

    let sql = concat!(
        "SELECT a, b, d ",
        "FROM t1 JOIN t2 ON a = c ",
        "ORDER BY b ASC ",
        "LIMIT 3"
    );

    let plan = ctx.create_logical_plan(&sql)?;
    let plan = ctx.optimize(&plan)?;
    let plan = ctx.create_physical_plan(&plan)?;

    let batches = collect(plan).await?;
    let formatted = arrow::util::pretty::pretty_format_batches(&batches).unwrap();
    let actual_lines: Vec<&str> = formatted.trim().lines().collect();

    let expected = vec![
        "+---+----+----+",
        "| a | b  | d  |",
        "+---+----+----+",
        "| a | 1  | 1  |",
        "| b | 10 | 10 |",
        "| c | 10 | 10 |",
        "+---+----+----+",
    ];

    assert_eq!(expected, actual_lines);

    Ok(())
}

{code}

[alamb]

DataFusion now requires tokio 1.x so if you tried to run this program using tokio 0.2 you'll get some sort of strange runtime error

[alamb]

I don't think this is relevant anymore