version=3
# mangle the alpha/beta/rc tags
opts=uversionmangle=s/(\d)[_\.\-\+]?((RC|rc|pre|dev|beta|alpha)\d*)$/$1~$2/ \
http://www.rust-lang.org/install.html \
https://static.rust-lang.org/dist/rustc-(\d+\.\d+\.\d+-+.+)-src\.tar\.gz