Can't build from source

[yongqli]

Installing from source using ./x.py build && sudo ./x.py dist --install, I get:

Build completed successfully in 0:29:55
Password:
info: looks like you are running this command under `sudo`
      and so in order to preserve your $HOME this will now
      use vendored sources by default. Note that if this
      does not work you should run a normal build first
      before running a command like `sudo make install`
error: failed to load source for a dependency on `num_cpus`

Caused by:
  Unable to update registry https://github.com/rust-lang/crates.io-index

Caused by:
  failed to update replaced source `registry https://github.com/rust-lang/crates.io-index`

Caused by:
  failed to read root of directory source: /Users/yongqli/projects/rust/src/vendor

[russmack]

Similar to #40108

[Mark-Simulacrum]

Closing in favor of #40108.