Global `cargo-features`

[flippette]

Problem

Currently it's not possible as far as I'm aware of to use cargo-features in $CARGO_HOME/config.toml, even when using a nightly build. Am I missing something?

Proposed Solution

No response

Notes

No response

[weihanglo]

AFAIK, that is intentional. cargo-features is for enabling Cargo.toml extensions for a certain Cargo.toml, whereas a config.toml is more like an environment setting. This is documented in "Unstable Features" chapter in The Cargo Book.

I'd like to know which feature you want to use but is blocked. Having a more specific example may help. Thank you.

[flippette]

I wanted to do something similar to this:

cargo-features = ["profile-rustflags", "codegen-backend"]

[profile.dev]
codegen-backend = "cranelift"

[profile.rel_local]
inherits = "release"
rustflags = ["-Ctarget-cpu=native"]

[flippette]

I managed to work around profile.rel_local with this:

(.cargo/config.toml)

[alias]
"i" = "install --config configs/install.toml

(.cargo/configs/install.toml)

[env]
RUSTFLAGS = ["-Ctarget-cpu=native"]

Yet I'm still unsure how to work around profile.dev since unlike RUSTFLAGS, there doesn't seem to be any environment variables associated with codegen-backend.

[weihanglo]

My poor memomry! I found this is a duplicate of #9926. I'll close it in favor of that. We could have more discussions there. Thank you!

[weihanglo]

Reopen this as the feature in #9926 has been stabilized. It is more clear to jot down notes on this issue.

Cargo team talked about this in today's meeting. The team decided not to have a general purpose way enabling features via configuration (.cargo/config.toml). Instead, we will enable -Z flag for an unstable Cargo syntax case by case.

For #11552 in [profile] Cargo should allow

• rustflags option, and
• codegen-backend option

to be set via config.toml.