cargo-revs.txt doesn't contain revs 😢😢😢

[carols10cents]

So long yak hair short, I wanted to be able to see if a particular commit to cargo was shipped with a particular released version of rustc. Unless I'm missing something, this information isn't straightforward to find anywhere!

I got really excited when I saw the cargo-revs.txt file in this repo, though, finally! Here it is! The git rev SHAs that were shipped with rustc! Oh wait-- it's only the date of the nightly that was used :( :( :( Which isn't always the last commit on that date...

So then I found the nightly cargo trigger of buildbot's, went to the build for a particular date (say, 2016-08-21) and that page says "got revision 109cb7c33d426044d141457049bd0fffaca1327c" which matches what I see if I do rustup default beta (since beta is 1.12.0 right now) and say cargo --version: cargo 0.13.0-nightly (109cb7c 2016-08-19).

I did that with other versions until buildbot ran out of builds to give me (it looks like it only keeps the last 500), so I think I have the correct SHAs.

Even though rust-packaging doesn't need these revs, would it be terrible to include them in cargo-revs.txt for future human reference and parse them out and have the code ignore them?

I'm also about to open an issue with cargo about tagging these commits with something to indicate the rustc version they went with, so if that seems like a better solution then feel free to close this :)

Here's the SHAs that I found and the buildbot source links, let me know if you'd like a PR in any particular format if you're in favor of this!

1.0.0: 2015-04-30 ?????
1.1.0: 2015-05-16 a48358155c90467ed9c897930dd0da4614605dac https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/144
1.2.0: 2015-07-10 15b497b10c8261f09f15130595f696fcf29c3619 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/203
1.3.0: 2015-08-03 553b363bcfcf444c5bd4713e30382a6ffa2a52dd https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/228
1.4.0: 2015-09-14 833b947016f4fb5269ef4bc5448e4d79eb3b475b https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/271
1.5.0: 2015-10-27 e1ed9956e079a563796fb380871f4b67619f58ee https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/314
1.6.0: 2015-12-09 1af03beaffe9be40ae81ca39431c1f1651ef6b02 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/357
1.7.0: 2016-01-18 9ebfb9b6d2bad7f9640ae012fae686ceeab7b084 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/397
1.8.0: 2016-03-01 8fc3fd8df3857f3e77454c992458cd7baeeb622b https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/442
1.9.0: 2016-04-10 10ddd7d5b3080fb0fa6c720cedca64407d4ca2f9 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/484
1.10.0: 2016-05-22 259324cd8f9bb6e1068a3a2b77685e90fda3e3b6 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/526
1.11.0: 2016-07-05 6b98d1f8abf5b33c1ca2771d3f5f3bafc3407b93 https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/567
1.12.0: 2016-08-21 109cb7c33d426044d141457049bd0fffaca1327c https://buildbot.rust-lang.org/builders/nightly-dist-cargo-trigger/builds/614

[brson]

I believe you can get the cargo sha for a particular revision of rustc out of the manifest files at e.g. https://static.rust-lang.org/dist/2016-09-27/channel-rust-nightly.toml. Somewhere in there is information about the associated cargo package, and I believe the cargo version number and commit sha.

[brson]

Stable manifests are at e.g. https://static.rust-lang.org/dist/channel-rust-1.12.0.toml