Why are Rust executables so huge?

Question

Just having found Rust and having read the first two chapters of the documentation, I find the approach and the way they defined the language particularly interesting. So I

Answer 1

For an overview of all of the ways to reduce the size of a Rust binary, see the min-sized-rust repository.

The current high level steps to reduce binary size are:

1. Use Rust 1.32.0 or newer (which doesn't include jemalloc by default)
2. Add the following to Cargo.toml

[profile.release]
opt-level = 'z'     # Optimize for size.
lto = true          # Enable Link Time Optimization
codegen-units = 1   # Reduce number of codegen units to increase optimizations.
panic = 'abort'     # Abort on panic

3. Build in release mode using cargo build --release
4. Run strip on the resulting binary.

There is more that can be done using nightly Rust, but I'll leave that information in min-sized-rust as it changes over time due to the use of unstable features.

You can also use #![no_std] to remove Rust's libstd. See min-sized-rust for details.