cargo prints unrelated warnings on cargo install --git

[matthiaskrgr]

Problem

When cargo installing a gitrepo project, cargo prints warnings of the workspace in the current cwd altough the workspace is completely unrelated and not touched.

Steps

1. cd into the rustc repo @ 43bec40138bab10c08ac916bff2f2f81b2b70669
2. cargo install --git https://github.com/matthiaskrgr/cargo-cache cargo-cache
3. During install, cargo will print

warning: patch for the non root package will be ignored, specify patch at the workspace root:
package:   /home/matthias/vcs/github/rust/src/tools/rls/Cargo.toml
workspace: /home/matthias/vcs/github/rust/Cargo.toml
    Updating git repository `https://github.com/matthiaskrgr/cargo-cache`

although the current workspace/cwd is completely unrelated to the cargo install command.

Possible Solution(s)

Notes

Output of cargo version:

cargo 1.47.0-nightly (ab32ee88d 2020-08-10)
release: 1.47.0
commit-hash: ab32ee88dade1b50c77347599e82ca2de3fb8a51
commit-date: 2020-08-10

[ehuss]

I believe this is due to this code which uses the workspace to provide better error messages for flags like --bin without an argument. That should probably be restructured somehow, though I'm not sure how. Maybe only build and pass in the workspace if --path is used (otherwise pass in None)?

[Rustin170506]

Can I working on this?

[ehuss]

@Rustin-Liu Go ahead! Let me know if you have any questions.

[ehuss]

Oh, wait, I just noticed there's already a PR open for this. Sorry about that!

[Rustin170506]

Oh, wait, I just noticed there's already a PR open for this. Sorry about that!

Got it. Thanks!