message: Pin nightlies temporarily
diff: @@ -28,7 +28,8 @@ matrix:
  - env: TARGET=x86_64-unknown-linux-gnu
  ALT=i686-unknown-linux-gnu
  - rust: nightly
  + # FIXME(rust-lang/rust#46271) should use just `nightly`
  + rust: nightly-2017-11-20
  install:
  - mdbook --help || cargo install mdbook --force
  script:
  