Add unstable --print-command-list flag

[taiki-e]

Closes #172

 --print-command-list
    Print commands without run (Unstable).

$ cargo hack check --each-feature --include-deps-features --print-command-list
cargo check --manifest-path Cargo.toml --no-default-features
cargo check --manifest-path Cargo.toml --no-default-features --features anyhow/backtrace
cargo check --manifest-path Cargo.toml --no-default-features --features anyhow/default
cargo check --manifest-path Cargo.toml --no-default-features --features anyhow/std
cargo check --manifest-path Cargo.toml --no-default-features --features ctrlc/termination
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/arbitrary
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/quickcheck
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/rayon
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/rustc-rayon
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/serde
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/serde-1
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/std
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/test_debug
cargo check --manifest-path Cargo.toml --no-default-features --features indexmap/test_low_transition_point
cargo check --manifest-path Cargo.toml --no-default-features --features libc/align
cargo check --manifest-path Cargo.toml --no-default-features --features libc/const-extern-fn
cargo check --manifest-path Cargo.toml --no-default-features --features libc/default
cargo check --manifest-path Cargo.toml --no-default-features --features libc/extra_traits
cargo check --manifest-path Cargo.toml --no-default-features --features libc/rustc-dep-of-std
cargo check --manifest-path Cargo.toml --no-default-features --features libc/rustc-std-workspace-core
cargo check --manifest-path Cargo.toml --no-default-features --features libc/std
cargo check --manifest-path Cargo.toml --no-default-features --features libc/use_std
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/alloc
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/arbitrary_precision
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/default
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/float_roundtrip
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/indexmap
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/preserve_order
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/raw_value
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/std
cargo check --manifest-path Cargo.toml --no-default-features --features serde_json/unbounded_depth
cargo check --manifest-path Cargo.toml --no-default-features --features slab/default
cargo check --manifest-path Cargo.toml --no-default-features --features slab/serde
cargo check --manifest-path Cargo.toml --no-default-features --features slab/std
cargo check --manifest-path Cargo.toml --no-default-features --features toml_edit/default
cargo check --manifest-path Cargo.toml --no-default-features --features toml_edit/easy
cargo check --manifest-path Cargo.toml --no-default-features --features toml_edit/perf
cargo check --manifest-path Cargo.toml --no-default-features --features toml_edit/serde

[leighmcculloch]

I think the output looks great 👏🏻. I'm going to try using it in a GitHub Action's build and will report back how it goes.

[leighmcculloch]

@taiki-e Thoughts on including this in a release?

[taiki-e]

I think the +<toolchain> in the output should be removed as it limits the reusability of the output, but once that is done, I think we can merge this

[taiki-e]

bors r+

[bors]

Build succeeded:

• ci

[leighmcculloch]

I think the +<toolchain> in the output should be removed as it limits the reusability of the output,

Maybe whether it is provided in the output or not should be based on if it is explicitly set in the input command?

That way if a user specifies it, it is retained.

[taiki-e]

Maybe whether it is provided in the output or not should be based on if it is explicitly set in the input command?

Old version of this PR just displayed the toolchain currently in use. +<toolchain> specified by the user precedes the subcommand, and cargo passes the corresponding cargo for that toolchain as a CARGO environment variable to the subcommand. So, it is not always easy to determine if +<toolchain> was specified by the user.

[taiki-e]

Published in 0.5.28.

[taiki-e]

FYI, --partition added in #253 is the way that can replace this in many use cases and is much easier to use.

[leighmcculloch]

💯, thanks for mentioning this here. It'd significantly simplify what I've used the print command for.