By request of AoC creator, I haven't included the input files (e.g. src/input/day01.txt). Log into the Advent of Code site and save the inputs there to the src/input/ folder.

To run all days: cargo run.

To run a specific day and/or part: cargo run -- --day 1 --part 1.

To run in super-fast prod mode: cargo run --release.

To run with debug logs enabled: RUST_LOG=debug cargo run.

To run all the tests against included test input files: RUST_LOG=debug cargo test -- --no-capture.

To run the tests for a specific day and/or part: RUST_LOG=debug cargo test day01::test::test_part1 -- --no-capture.

Benchmarks

Because this is over-engineered, I've included benchmarks for each day's solution. Because, why not?

To run benchmarks: cargo bench. Or a specific day and/or part: cargo bench -- "day02 part1".

Results

These were all run on my personal machine, an AMD Ryzen 9 3900X 12-Core Processor with 32 GB RAM, on Linux (WSL).

Timings are given as: [lower-bound best-estimate upper-bound]

Day	Part 1	Part 2
01	[101.34 µs 101.95 µs 102.61 µs]	[105.90 µs 106.40 µs 106.95 µs]
02	[165.59 ms 166.60 ms 167.65 ms]	[184.17 ms 185.25 ms 186.42 ms]