Re: [PROPOSAL] Builder, a build system integration for Emacs

[Gregory Heytings]

> Where does cargo get the list of libraries to consider using?

The dependencies of a Rust program/library are specified (manually) by the 
author of that program/library, in a (structured) text file.  The source 
code of the libraries on which the program/library depends are downloaded 
(by Cargo) from the crates.io registry, and kept in a local cache 
(CARGO_HOME, by default $HOME/.cargo).

> Are all the libraries in that default list free/libre?

No, some libraries/programs in the crates.io registry are non-free (but 
their source code is always available).  This is because, to use your 
words in your other post, the crates.io registry is a "repo site where in 
principle anyone can put a program", and not a list of "programs that in 
principle you may wish to install side by side in one computer".

As I said in an earlier post, there are currently 115402 available 
libraries/programs in the crates.io registry, and out of these the vast 
majority (at least 110000) use free software licenses.  The recommended 
license for Rust libraries/programs is a dual MIT/Apache-2.0 (which is how 
Rust itself is licensed), but users are not forced to use these licenses.