Fallback resource locators for versioned dependencies?

[oblitum]

I'm assuming cargo toml supports specifying version for dependencies. I know I can depend upon a git remote, and have tried that, but I didn't check whether checking out specific versions from a repository is possible? (for instance, checking out a given tag that corresponds to a given version (automatically happening after cloning) or are versioned dependencies tied to the toml version field solely? So this talk about repo tags, etc, doesn't make sense).

Said that, and that I've heard in the future there will be a centralized source like rubygems.org, which eventually will be down, I'm wondering whether it would be nice, or whether there's support for it already, to have multiple fallback options for versioned dependencies from several remote sources.

I'm emphasizing version because since there're mechanisms to get versioned stuff, from where it comes from is of little importance, and being able to specify multiple sources from client-side seems good to have.

Sorry if I'm being too vague here, I just started using it another day and these things came to my mind, I'm can't say whether there's support for anything I've asked. Particularly, having a package manager that can checkout tagged repos (with fallback urls) would be nice and simple, it seems. Beyond promoting tagging, which is healthy I guess. Also, employing this further, could even lead to a convention (vs configuration) of just not publishing versions in the dependency toml but just let this to the tags.

[sfackler]

You can already depend on a specific branch, tag or commit of a dependency's git repo.

[oblitum]

@sfackler thanks for the info, are there docs anywhere? crates.io is quite terse currently, and there's no wiki.

[oblitum]

@sfackler ah, nevermind, I've checked the "manifest format" link.

[alexcrichton]

Lots of this still needs to develop around bringing the registry online, but at this time we are not going to require that the tags in git stay in sync with released versions in the registry. We may be able to add various mirrors for the registry, but the plan is not currently to fall back to downloading from source.

We can of course revisit this, however, if it becomes a problem. For now though, I'm going to close this and possibly reopen once we have some experience with the registry.

[oblitum]

It's being frustating for me to build cargo. I just built it but I had to make more than three times because it got stuck downloading some dependency at random, and failed. I then recalled this issue...