Building a Binary

Created at: 2025-02-27

Inside a project created with cargo (Cargo.toml), run:

cargo build

This will create a binary in target/debug/<bin_name>. Also:

Running cargo build for the first time also causes Cargo to create a new file at the top level: Cargo.lock. This file keeps track of the exact versions of dependencies in your project. This project doesn’t have dependencies, so the file is a bit sparse. You won’t ever need to change this file manually; Cargo manages its contents for you.

Profile

You can change the profile in which you want to generate the binary. For example:

cargo build --profile=release

This will create a binary in target/release/<bin_name>. The release command will have run with the following settings:

[profile.release]
opt-level = 3  # similar to gcc -O3
debug = false  # no debug info at all
# Platform-specific. controls whether debug information, if generated, is
# either placed in the executable itself or adjacent to it.
split-debuginfo = '...' 
strip = "none"  # Whether to strip symbols or debuginfo from binary
debug-assertions = false  # enables the debug_assert! macro. Not for prod.
overflow-checks = false
lto = false  # longer linker time at the expense of more optimisation
panic = 'unwind'
incremental = false  # incremental compilation. Makes compilation faster
codegen-units = 16
rpath = false

check

Sometimes, building the binary can take a lot of time. If all you want to do is to check that the code would compile, you can run:

cargo check
# cargo check --profile=release