"no matching package named ffmpeg-sys found" but required version is part of the index

[AndiDog]

Getting this error while building a project that needs crate "ffmpeg" (which in turn currently requires ffmpeg-sys 2.8.3). I have path overrides in ".cargo\config", but that does not seem to matter since Cargo does not consider them (I removed the overrides and get the same issue).

Updating registry https://github.com/rust-lang/crates.io-index
error: no matching package named ffmpeg-sys found (required by ffmpeg)
location searched: registry https://github.com/rust-lang/crates.io-index
version required: ^2.8.3

The searched version is apparently on the index (with suffixes, e.g. "2.8.3-1"):
https://github.com/rust-lang/crates.io-index/blob/master/ff/mp/ffmpeg-sys

Is this a bug?!

(using Rust 1.9 nightly on Windows, cargo 0.10.0-nightly (10ddd7d 2016-04-08))

Update: Just checked on Mac OS X with exact same files. Was still working there because I used an older Cargo (cargo 0.9.0-nightly (f052d99 2016-01-24)). Updated to nightly now and I get the same error (cargo 0.10.0-nightly (10ddd7d 2016-04-08)) as on Windows 🤔.

[alexcrichton]

I believe this is the same #2381, but the gist is that ffmpeg-sys has only been released with prerelease versions so you'll have to pin to those specifically.