cargo-install unnecessarily rebuilds everything

[Keruspe]

Starting with rust 1.27, if I run cargo build --release then cargo install, the latter syncs its crates.io local copy and rebuilds everything.
This didn't happen with rust 1.26.

Might be related to the latest failure in rust-lang/rust#51717 (comment) ?

[ehuss]

I think this change was intentional, see #5327. You should have gotten a warning:

warning: To build the current package use `cargo build`, 
to install the current package run `cargo install --path .`

[Keruspe]

@ehuss I fail to see how that could be related.

I'm a distribution packager and our install phase doesn't have access to the network so resyncing crates.io breaks stuff, and rebuilding everything that was built just before during the compile phase doesn't seem necessary...

[Keruspe]

Actually, this is probably a duplicate of #5662

[ehuss]

Ah, sorry, I misunderstood. Indeed using cargo install in a workspace does not seem to be working as intended.

[alexcrichton]

Indeed I believe this is a duplicate! Closing in favor of #5662