message: avoid recompiling miri for 2nd test run; avoid unreadable output due to backtraces
  also some travis config cleanup
diff: language: rust
  cache: cargo
  +rust:
  +- nightly
  os:
  -- osx
  - linux
  +- osx
  -rust:
  -- nightly
  before_script:
  # mac os weirdness (https://github.com/travis-ci/travis-ci/issues/6307)
  - curl -sSL https://rvm.io/mpapis.asc | gpg --import -
  - rvm get stable
  # in a cronjob, use latest (not pinned) nightly
  - if [ "$TRAVIS_EVENT_TYPE" = cron ]; then rustup override set nightly; fi
  -# actual travis code
  +# prepare
  - export PATH=$HOME/.local/bin:$PATH
  - rustup target add i686-unknown-linux-gnu
  - rustup target add i686-pc-windows-gnu
  - rustup target add i686-pc-windows-msvc
  - rustup component add rust-src
  - cargo install xargo || echo "skipping xargo install"
  -- export RUST_SYSROOT=$HOME/rust
  +
  script:
  - set -e
  - |
  # Test and install plain miri
  cargo build --release --all-features &&
  - RUST_BACKTRACE=1 cargo test --release --all-features --all &&
  + cargo test --release --all-features &&
  cargo install --all-features --force
  - |
  # test that the rustc_tests binary compiles
  @@ -55,7 +55,8 @@ script:
  cd ..
  - |
  # and run all tests with full mir
  - cargo test --release
  + cargo test --release --all-features
  +
  notifications:
  email:
  on_success: never
  