Profiles

Profiles let you override rx configuration for different contexts – CI, development, release builds, or any custom scenario.

Defining a profile

Add a [profile.<name>] section to your rx.toml. Each profile can override build, lint, test, and env settings:

[profile.ci]
build = { cache = false, jobs = 2 }
lint = { severity = "deny" }
test = { runner = "nextest" }
env = { CI = "true" }

Using a profile

Pass --profile <name> to any rx command:

rx --profile ci build
rx --profile ci test
rx --profile ci lint

The profile flag is a global flag, so it must appear before the subcommand.

How merging works

When a profile is active, rx starts with the base configuration (global + project) and then applies the profile overrides on top. Only the fields explicitly set in the profile are changed; everything else keeps its base value.

For example, given this configuration:

[build]
linker = "mold"
cache = true
jobs = 0

[profile.ci]
build = { cache = false, jobs = 2 }

Running rx --profile ci build uses:

Common profiles

CI profile

Disable caching (CI runners are ephemeral) and enforce strict linting:

[profile.ci]
build = { cache = false, jobs = 2 }
lint = { severity = "deny" }
test = { runner = "nextest" }
env = { CI = "true", RUST_BACKTRACE = "1" }

Release profile

Use the system linker for maximum compatibility:

[profile.release]
build = { cache = true }
env = { RUSTFLAGS = "-C target-cpu=native" }

Minimal profile

Fast iteration during development:

[profile.quick]
build = { cache = true }
lint = { severity = "warn" }

Profile environment variables

The env field in a profile merges with (and overrides) the base [env] section:

[env]
RUST_BACKTRACE = "1"
RUST_LOG = "info"

[profile.ci]
env = { RUST_LOG = "warn", CI = "true" }

With --profile ci, RUST_BACKTRACE remains "1", RUST_LOG becomes "warn", and CI is set to "true".

Overridable fields