Variables Proposal

vars_proposal.md

Variables in manifest

Goals:

• Avoid repeating values
• Make it easy to interact with a full tree of tasks

[vars]
profile = "--release"

[tasks.install]
cmd = "cargo install {{ profile }}"

[tasks.test]
depends-on = ["install"]
cmd = "cargo test {{ profile }}"

pixi run test
# Runs:
# cargo install --release
# cargo test --release

pixi run --var profile=--debug test
# Runs:
# cargo install --debug
# cargo test --debug

Cross environments

[vars]
profile = "--release"

[tasks.install]
cmd = "cargo install {{ profile }}"

[feature.test.vars]
profile = "--debug"

[feature.test.tasks.test]
depends-on = ["install"]
cmd = "cargo test {{ profile }}"

[environments]
test = ["test"]

pixi run install
# Runs:
# cargo install --release

pixi run test
# Runs:
# cargo install --release
# cargo test --debug    

pixi run --environment test test
# Runs:
# cargo install --debug
# cargo test --debug

pixi run --var "profile=--profile" test
# Runs:
# cargo install --profile
# cargo test --profile

Slightly adapted example

[vars]
profile = "--release"

[tasks.install]
cmd = "cargo install {{ profile }}"

[feature.test.vars]
profile = "--debug"

[feature.test.tasks.test]
depends-on = ["install"]
cmd = "cargo test {{ profile }}"

[environments]
test = { features= ["test"], no-default-feature = true }

pixi run install
# Runs:
# cargo install --release

pixi run test
# Runs:
# cargo install --release
# cargo test --debug    

pixi run --environment test test
# Task `install` doesn't exist in environment "test", so it will run in environment "default" instead.
# Runs:
# cargo install --debug
# cargo test --debug

pixi run --var "profile=--profile" test
# Runs:
# cargo install --profile
# cargo test --profile

Merging vars

We need to take care when we merge vars. The current behaviour is that, that the first feature wins:

[feature.test1.vars]
profile = "--debug"

[feature.test1.tasks]
start = "cargo test {{ profile }}"

[feature.test2.vars]
profile = "--release"

[envs]
test = ["test2", "test1"]

Running should behaves as follows:

$ pixi run start
cargo test --release

Keep in mind, that unless no-default-feature=true, the default feature is always implicitly appended:

test = ["test2", "test1", "default"]