docs.rs build failure for ez-ffmpeg: Unable to fetch FFmpeg source due to network restrictions

[YeautyYE]

Crate name

ez-ffmpeg

Build failure link

https://docs.rs/crate/ez-ffmpeg/0.1.1/builds/1836231

Additional details

I'm encountering an issue when generating documentation on docs.rs for my project, ez-ffmpeg. The project depends on ffmpeg-sys-next and in version 0.1.1 I've enabled its build feature. This feature is necessary because the default Linux environment does not include FFmpeg 7.1, resulting in missing items like ffmpeg_sys_next::AVChannelOrder::AV_CHANNEL_ORDER_UNSPEC.

To resolve these missing components, the build feature compiles FFmpeg 7.1 during the build process. However, docs.rs restricts external network access, and the build script fails when attempting to clone the FFmpeg source from GitHub. An excerpt from the logs is as follows:

Cloning into 'ffmpeg-7.1'...
fatal: unable to access 'https://github.com/FFmpeg/FFmpeg/': Could not resolve host: github.com
...
called `Result::unwrap()` on an `Err` value: Custom { kind: Other, error: "fetch failed" }

I understand that the network restrictions on docs.rs are in place for security and reliability, but this leaves me with no alternative method to generate documentation for ez-ffmpeg. Is there a recommended workaround or configuration option (for example, an environment variable or a docs.rs-specific flag) that would allow skipping or handling the network-dependent build step? Any guidance or suggestions on how to proceed would be greatly appreciated.

Environment:

• rustc version: 1.87.0-nightly (b74da9613 2025-03-06)
• docs.rs version: 0.6.0 (004a02c 2025-03-05)

Thank you for your help!

[syphar]

A good start is always our https://docs.rs/about/builds page.

Generally people solve this issue by either

• adding the necessary package to our https://github.com/rust-lang/crates-build-env/. I could also imagine the newer ffpmeg version might be available after the ubuntu upgrade? Update to Ubuntu 24.04 (Noble) based on PR#151 crates-build-env#168
• vendoring the source
• using https://docs.rs/about/metadata to build a version of the crate that doesn't need the third party source, and builds just what's needed for the docs. This would be what you call " allow skipping or handling the network-dependent build step", and would be a change to ffmpeg-sys-next.

Often it also helps to look at how the other library (in this case, ffmpeg-sys-next) builds its docs.

I also have a hunch that the ffmpeg version included in rust-lang/crates-build-env#168 would suffice?

[syphar]

In any case, we will never allow network access.