language: rust
rust:
  - stable
  - beta
  - nightly
matrix:
  allow_failures:
    - rust: nightly
language: rust
rust:
  - stable
  - beta
  - nightly
matrix:
  allow_failures:
#    stable and beta don't support proc macros ATM
    - rust: stable
    - rust: beta
Allow failures for stable and beta, disallow for nightly
Allow failures for stable and beta, disallow for nightly
