A noob Rust developer, interested in quantitative trading and trying to basically write a parquet file containing mock Tick data. This is how the code looks like.

use polars::prelude::{Column, DataFrame, ParquetWriter};
use quant_data_platform::tick::{Side, Tick, TimestampNs};
use std::error::Error;
use std::fs;
use std::path::Path;

const DEFAULT_ROWS: usize = 10u32.pow(7) as usize;

fn main() -> Result<(), Box<dyn Error>> {
    let rows: usize = DEFAULT_ROWS;
    let mut instruments: Vec<u8> = Vec::with_capacity(rows);
    let mut sides: Vec<&str> = Vec::with_capacity(rows);
    let mut prices: Vec<u32> = Vec::with_capacity(rows);
    let mut volumes: Vec<u8> = Vec::with_capacity(rows);
    let mut timestamps_ns: Vec<TimestampNs> = Vec::with_capacity(rows);
    for _ in 0..rows {
        let tick: Tick = Tick::get_random_tick();

        instruments.push(tick.instrument);
        sides.push(match tick.side {
            Side::BUY => "BUY",
            Side::SELL => "SELL",
        });
        prices.push(tick.price);
        volumes.push(tick.volume);
        timestamps_ns.push(tick.ts);
    }

    let mut df: DataFrame = DataFrame::new_infer_height(vec![
        Column::new("instrument".into(), instruments),
        Column::new("side".into(), sides),
        Column::new("price".into(), prices),
        Column::new("volume".into(), volumes),
        Column::new("ts_ns".into(), timestamps_ns),
    ])?;
    let filename: String = String::from("data_dump/mock_data.parquet");
    if let Some(parent) = Path::new(&filename).parent() {
        fs::create_dir_all(parent)?;
    }
    let file: fs::File = fs::File::create(&filename)?;
    let bytes: u64 = ParquetWriter::new(file).finish(&mut df)?;
    println!("wrote {rows} ticks to file {output} of {bytes} bytes");
    Ok(())
}

And this is Cargo.toml.

[package]
name = "quant-data-platform"
version = "0.1.0"
edition = "2024"

[dependencies]
chrono = "0.4.45"
polars = { version = "0.54.4", features = ["parquet", "dtype-u8", "lazy"] }
rand = "0.10.2"

The error I am facing seems to be coming right out of polars, rather than my own code. Here is the stacktrace.

error[E0599]: no variant, associated function, or constant named `StringExpr` found for enum `polars_plan::plans::IRFunctionExpr` in the current scope
    --> /home/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/polars-stream-0.54.4/src/physical_plan/lower_expr.rs:1533:37
     |
1533 |                     IRFunctionExpr::StringExpr(IRStringFunction::Strptime(ref dtype, ref options)),
     |                                     ^^^^^^^^^^ variant, associated function, or constant not found in `polars_plan::plans::IRFunctionExpr`
     |
help: there is a variant with a similar name
     |
1533 -                     IRFunctionExpr::StringExpr(IRStringFunction::Strptime(ref dtype, ref options)),
1533 +                     IRFunctionExpr::StructExpr(IRStringFunction::Strptime(ref dtype, ref options)),
     |

error[E0433]: cannot find type `IRStringFunction` in this scope
    --> /home/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/polars-stream-0.54.4/src/physical_plan/lower_expr.rs:1533:48
     |
1533 |                     IRFunctionExpr::StringExpr(IRStringFunction::Strptime(ref dtype, ref options)),
     |                                                ^^^^^^^^^^^^^^^^ use of undeclared type `IRStringFunction`
     |
help: an enum with a similar name exists
     |
1533 -                     IRFunctionExpr::StringExpr(IRStringFunction::Strptime(ref dtype, ref options)),
1533 +                     IRFunctionExpr::StringExpr(IRStructFunction::Strptime(ref dtype, ref options)),
     |

Some errors have detailed explanations: E0433, E0599.
For more information about an error, try `rustc --explain E0433`.
error: could not compile `polars-stream` (lib) due to 2 previous errors

Does it mean a bug with the polars library itself? I have used polars extensively for data engineering with Python, but this is the first time I am trying this with Rust. So far as I see, the error points to the library code rather than my own.

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