Problem

I'm having trouble building some project with cargo because it fails to fetch a specific package from sources (with a given version/tag).

While I don't see why this is necessarily cargo's fault rather than the project's fault, the command output is kindly suggesting me to fill a bug report, so here I am.

Steps

1. Use cargo 1.44.0-nightly (390e8f2 2020-04-07), got it from updating with rustup.
2. Clone the following project (and checkout a specific commit, just to be sure):

$ git clone git@gitlab.freedesktop.org:gstreamer/gst-plugins-rs.git
$ cd gst-plugins-rs && git checkout bd90d1d9

[EDIT] 2-bis. Project page if you can't clone it ssh-style: https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs [/EDIT]
3. Run cargo build --verbose inside the resulting project folder.

This is the output I get:

$ cargo build --verbose
error: failed to download `gio-sys v0.7.0 (https://github.com/gtk-rs/sys#508d9264)`

Caused by:
  unable to get packages from source

Caused by:
  failed to find gio-sys v0.7.0 (https://github.com/gtk-rs/sys#508d9264) in path source
note: this is an unexpected cargo internal error
note: we would appreciate a bug report: https://github.com/rust-lang/cargo/issues/
note: cargo 1.44.0-nightly (390e8f245 2020-04-07)

Possible Solution(s)

• Have an actual verbose output in this case when using the --verbose flag: you get the same amount of info without using said flag.
• If this is not an actual cargo internal error and just a project-side error, then do not display it as such.

Notes

Output of cargo version: cargo 1.44.0-nightly (390e8f2 2020-04-07)
Output of rustc --version: rustc 1.44.0-nightly (3712e11a8 2020-04-12)
OS being used: ArchLinux
Release channel: Nightly