Bisects rustc toolchains with rustup

Usage: cargo bisect-rustc [OPTIONS] [-- <COMMAND_ARGS>...]

Arguments:
  [COMMAND_ARGS]...  Arguments to pass to cargo or the file specified by --script during tests

Options:
  -a, --alt                     Download the alt build instead of normal build
      --access <ACCESS>         How to access Rust git repository [default: github] [possible
                                values: checkout, github]
      --by-commit               Bisect via commit artifacts
  -c, --component <COMPONENTS>  additional components to install
      --end <END>               Right bound for search (*with* regression). You can use a date
                                (YYYY-MM-DD), git tag name (e.g. 1.58.0) or git commit SHA.
      --force-install           Force installation over existing artifacts
  -h, --help                    Print help (see more with '--help')
      --host <HOST>             Host triple for the compiler [default: [..]]
      --install <INSTALL>       Install the given artifact
      --preserve                Preserve the downloaded artifacts
      --preserve-target         Preserve the target directory used for builds
      --prompt                  Manually evaluate for regression with prompts
      --regress <REGRESS>       Custom regression definition [default: error] [possible values:
                                error, success, ice, non-ice, non-error]
      --script <SCRIPT>         Script replacement for `cargo build` command
      --start <START>           Left bound for search (*without* regression). You can use a date
                                (YYYY-MM-DD), git tag name (e.g. 1.58.0) or git commit SHA.
  -t, --timeout <TIMEOUT>       Assume failure after specified number of seconds (for bisecting
                                hangs)
      --target <TARGET>         Cross-compilation target platform
      --term-new <TERM_NEW>     Text shown when a test does match the condition requested
      --term-old <TERM_OLD>     Text shown when a test fails to match the condition requested
      --test-dir <TEST_DIR>     Root directory for tests [default: .]
  -v, --verbose...              
  -V, --version                 Print version
      --with-dev                Download rustc-dev [default: no download]
      --with-src                Download rust-src [default: no download]
      --without-cargo           Do not install cargo [default: install cargo]

Examples:
    Run a fully automatic nightly bisect doing `cargo check`:
    ```
    cargo bisect-rustc --start 2018-07-07 --end 2018-07-30 --test-dir ../my_project/ -- check
    ```

    Run a PR-based bisect with manual prompts after each run doing `cargo build`:
    ```
    cargo bisect-rustc --start 6a1c0637ce44aeea6c60527f4c0e7fb33f2bcd0d /
      --end 866a713258915e6cbb212d135f751a6a8c9e1c0a --test-dir ../my_project/ --prompt -- build
    ```