* guix/build-system/cargo.scm (cargo-build): Add src output.
(private-keywords): Add #:outputs.
* guix/build/cargo-build-system.scm (configure): Use /share/rust-source
when replacing inputs.
(build, check): Don't do anything when there isn't a Cargo.lock file
present.
(install): Install sources to src output. When a Cargo.lock file is
present use cargo install to install binaries to out.
* guix/import/crate.scm (make-crate-sexp): Importer uses the src output
for crate inputs by default.
* guix/import/utils.scm (package-names->package-inputs, maybe-inputs,
maybe-native-inputs): Take an optional output argument.
* tests/crate.scm (crate->guix-package test): Update.
Problem reported by Francisco Gómez García <espectalll@kydara.com>.
David Craven