Feature request: add possibility to use system-wide installed packages

[jauhien]

Please, add a possibility for cargo to use system-wide installed dependencies during building (and not fetch and compile them). This is necessary for packaging software that uses cargo as a build system.

Related issue: https://github.com/Heather/gentoo-rust/issues/25

[steveklabnik]

Have you seen https://github.com/alexcrichton/link-config ?

[steveklabnik]

Also, this is a dup of #145

[alexcrichton]

Yes, I believe that this is a dupe of #145 as well.

[jauhien]

Yes, my bad, that's a dupe. Sorry, it was bad googling.

[alexcrichton]

No worries! Github doesn't always present the best interface for searching either!