trigger a re-build of the standard library; you have to clear the Miri build
cache manually (on Linux, `rm -rf ~/.cache/miri`).
* `MIRI_SYSROOT` (recognized by `cargo miri` and the Miri driver) indicates the sysroot to use. When
- using `cargo miri`, only set this if you do not want to use the automatically created sysroot. For
- directly invoking the Miri driver, this variable (or a `--sysroot` flag) is mandatory.
+ using `cargo miri`, this skips the automatic setup -- only set this if you do not want to use the
+ automatically created sysroot. For directly invoking the Miri driver, this variable (or a
+ `--sysroot` flag) is mandatory. When invoking `cargo miri setup`, this indicates where the sysroot
+ will be put.
* `MIRI_TEST_TARGET` (recognized by the test suite and the `./miri` script) indicates which target
architecture to test against. `miri` and `cargo miri` accept the `--target` flag for the same
purpose.