explain how to go back to rustup-managed Miri

diff --git a/src/tools/miri/CONTRIBUTING.md b/src/tools/miri/CONTRIBUTING.md
index b1e6b9c69d390846500fd6c4eaf5708fc76b697f..a2c86c3a8b23e74effd0c4d70e3d8c6044f1ba30 100644 (file)
--- a/src/tools/miri/CONTRIBUTING.md
+++ b/src/tools/miri/CONTRIBUTING.md
@@ -138,6 +138,9 @@ There's a test for the cargo wrapper in the `test-cargo-miri` directory; run
 `./run-test.py` in there to execute it. Like `./miri test`, this respects the
 `MIRI_TEST_TARGET` environment variable to execute the test for another target.
 
+Note that installing Miri like this will "take away" Miri management from `rustup`.
+If you want to later go back to a rustup-installed Miri, run `rustup update`.
+
 ### Using a modified standard library
 
 Miri re-builds the standard library into a custom sysroot, so it is fairly easy