message: README: mention to cargo update, mention rustup-toolchain-install-master
diff: @@ -55,7 +55,11 @@ Install Miri via `rustup`:
  rustup component add miri
  ```
  -If `rustup` says the `miri` component is unavailable, that's because not all nightly releases come with all tools. Check out [this website](https://rust-lang.github.io/rustup-components-history) to determine a nightly version that comes with Miri and install that, e.g. using `rustup install nightly-2019-03-28`.
  +If `rustup` says the `miri` component is unavailable, that's because not all
  +nightly releases come with all tools. Check out
  +[this website](https://rust-lang.github.io/rustup-components-history) to
  +determine a nightly version that comes with Miri and install that, e.g. using
  +`rustup install nightly-2019-03-28`.
  Now you can run your project in Miri:
  @@ -131,7 +135,17 @@ able to just `cargo build` Miri.
  In case this fails, your nightly might be incompatible with Miri master. The
  `rust-version` file contains the commit hash of rustc that Miri is currently
  tested against; you can use that to find a nightly that works or you might have
  -to wait for the next nightly to get released.
  +to wait for the next nightly to get released. You can also use
  +[`rustup-toolchain-install-master`](https://github.com/kennytm/rustup-toolchain-install-master)
  +to install that exact version of rustc as a toolchain:
  +```
  +rustup-toolchain-install-master $(cat rust-version) -c rust-src
  +```
  +
  +Another common problem is outdated dependencies: Miri does not come with a
  +lockfile (it cannot, due to how it gets embedded into the rustc build). So you
  +have to run `cargo update` every now and then yourself to make sure you are
  +using the latest versions of everything (which is what gets tested on CI).
  ### Testing the Miri driver
  [testing-miri]: #testing-the-miri-driver
  