How to get a release build with debugging information when using cargo?

Another option that I found that does not require changing Cargo.toml is to use the RUSTFLAGS environment variable:

$ RUSTFLAGS=-g cargo build --release

As of Rust 1.57, Cargo now allows for custom profiles. This allows you to define your own profile that adds debug information:

[profile.release-with-debug]
inherits = "release"
debug = true

You can then use that profile when building:

% cargo build --profile=release-with-debug
   Compiling buggin v0.1.0 (/tmp/buggin)
    Finished release-with-debug [optimized + debuginfo] target(s) in 0.48s

Prior to this version, or if you always wanted to have debugging information, you can modify the release profile to include debugging symbols:

[profile.release]
debug = true

Note that the release profile and the bench profile differ.

See also

  • Can tests be built in release mode using Cargo?
  • How to compile and run an optimized Rust program with overflow checking enabled
  • Does Cargo support custom profiles?

Or basically any of the top search results for "rust profiling":

  • Rust Profiling with Instruments and FlameGraph on OSX: CPU/Time
  • Profiling Rust applications on Linux
  • Profiling rust code with callgrind