install the current rustc nightly version that works with Miri:
```sh
-multirust update nightly-2016-04-11
+multirust update nightly-2016-04-21
```
## Build
```sh
-multirust run nightly-2016-04-11 cargo build
+multirust run nightly-2016-04-21 cargo build
```
## Run a test
```sh
-multirust run nightly-2016-04-11 cargo run -- \
- --sysroot $HOME/.multirust/toolchains/nightly-2016-04-11 \
+multirust run nightly-2016-04-21 cargo run -- \
+ --sysroot $HOME/.multirust/toolchains/nightly-2016-04-21 \
test/filename.rs
```
If you are using [rustup][rustup] (the name of the multirust rewrite in Rust),
the `sysroot` path will also include your build target (e.g.
-`$HOME/.multirust/toolchains/nightly-2016-04-11-x86_64-apple-darwin`). You can
+`$HOME/.multirust/toolchains/nightly-2016-04-21-x86_64-apple-darwin`). You can
see the current toolchain's directory by running `rustup which cargo` (ignoring
the trailing `/bin/cargo`).