Cargo bootstrap

Cargo is Rust's package manager. One of Cargo's build dependencies is Cargo, which poses a bit of a problem on platforms without readily-available binary bootstrap releases. This is an attempt to build a Cargo bootstrapper that only requires a working Rust compiler (bootstrapping rustc is left as an exercise to the reader).

The goal is to enable bootstrapping with any POSIX-compliant make utility (including bmake and gmake):

$ ARCH=x86_64 VENDOR=unknown TARGET_OS=freebsd make
rustc main.rs -o bootstrap
./bootstrap freebsd x86_64-unknown-freebsd
==> libc (rust-lang/libc)
Fetching...
Compiling...

==> bitflags (rust-lang/bitflags)
Fetching...
Compiling...

==> glob (rust-lang/glob)
Fetching...
Compiling...

==> log (rust-lang/log)
Fetching...
Compiling...

==> rand (rust-lang/rand)
Fetching...
Compiling...

==> regex (rust-lang/regex)
Fetching...
Compiling...

==> rustc_serialize (rust-lang/rustc-serialize)
Fetching...
Compiling...
[etc.]

This script doesn't quite work yet. Please file issues using the GitHub issue tracker.