docs.rs failed to build ostree-0.20.2

[jeckersb]

https://docs.rs/crate/ostree/latest

Just something I noticed in passing, looks like it needs ostree-devel or equivalent in the docs building environment, from https://docs.rs/crate/ostree/0.20.2/builds/2143047:

[INFO] [stderr]   pkg-config exited with status code 1
[INFO] [stderr]   > PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 pkg-config --libs --cflags ostree-1 'ostree-1 >= 0.0'
[INFO] [stderr] 
[INFO] [stderr]   The system library `ostree-1` required by crate `ostree-sys` was not found.
[INFO] [stderr]   The file `ostree-1.pc` needs to be installed and the PKG_CONFIG_PATH environment variable must contain its 

[jeckersb]

Looks like from https://docs.rs/about/builds#missing-dependencies that we need to add libostree-dev to https://github.com/rust-lang/crates-build-env/blob/master/linux/packages.txt

[cgwalters]

I thought it's possible though to build the docs without this by basically using #[cfg(docsrs)] to turn off trying to link the library. But obviously adding it is simple and works - I hadn't realized how many other libraries they pull in by default in the docsrs build now.