[est31]

Interesting question. Does RUSTDOCFLAGS="--extern-html-root-url std=file:///path/to/std/docs" cargo doc work? You can repeat it for std, core, alloc, proc-macro, etc.

[steveklabnik]

You need a -Z unstable-options in there too, but this does not work for me with the latest nightly.

[est31]

Hmm apparently there is a cargo feature for it now: https://github.com/rust-lang/cargo/blob/master/src/doc/src/r...

So something like this in .cargo/config:

[doc.extern-map]

std = "local"

And then cargo +nightly doc -Zrustdoc-map.

[steveklabnik]

Very cool!