diff --git a/rust-version b/rust-version
index df2bac877..0dc9ce843 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-2f3f27bf79ec147fec9d2e7980605307a74067f4
+9f32ccf35fb877270bc44a86a126440f04d676d0
diff --git a/src/tests/intro.md b/src/tests/intro.md
index b90c16d60..4fa63b83b 100644
--- a/src/tests/intro.md
+++ b/src/tests/intro.md
@@ -70,10 +70,12 @@ package tests:
 
 Tidy is a custom tool used for validating source code style and formatting
 conventions, such as rejecting long lines. There is more information in the
-[section on coding conventions](../conventions.md#formatting).
+[section on coding conventions](../conventions.md#formatting) or the [Tidy Readme].
 
 > Examples: `./x test tidy`
 
+[Tidy Readme]: https://github.com/rust-lang/rust/blob/master/src/tools/tidy/Readme.md
+
 
 ### Formatting
 
diff --git a/src/tests/running.md b/src/tests/running.md
index 317b65f98..482f3c425 100644
--- a/src/tests/running.md
+++ b/src/tests/running.md
@@ -339,9 +339,34 @@ results.  The Docker image is set up to launch `remote-test-server` and the
 build tools use `remote-test-client` to communicate with the server to
 coordinate running tests (see [src/bootstrap/src/core/build_steps/test.rs]).
 
-> **TODO**
->
-> - Is there any support for using an iOS emulator?
+To run on the iOS/tvOS/watchOS/visionOS simulator, we can similarly treat it as
+a "remote" machine. A curious detail here is that the network is shared between
+the simulator instance and the host macOS, so we can use the local loopback
+address `127.0.0.1`. Something like the following should work:
+
+```sh
+# Build the test server for the iOS simulator:
+./x build src/tools/remote-test-server --target aarch64-apple-ios-sim
+
+# If you already have a simulator instance open, copy the device UUID from:
+xcrun simctl list devices booted
+UDID=01234567-89AB-CDEF-0123-456789ABCDEF
+
+# Alternatively, create and boot a new simulator instance:
+xcrun simctl list runtimes
+xcrun simctl list devicetypes
+UDID=$(xcrun simctl create $CHOSEN_DEVICE_TYPE $CHOSEN_RUNTIME)
+xcrun simctl boot $UDID
+# See https://nshipster.com/simctl/ for details.
+
+# Spawn the runner on port 12345:
+xcrun simctl spawn $UDID ./build/host/stage2-tools/aarch64-apple-ios-sim/release/remote-test-server -v --bind 127.0.0.1:12345
+
+# In a new terminal, run tests via the runner:
+export TEST_DEVICE_ADDR="127.0.0.1:12345"
+./x test --host='' --target aarch64-apple-ios-sim --skip tests/debuginfo
+# FIXME(madsmtm): Allow debuginfo tests to work (maybe needs `.dSYM` folder to be copied to the target?).
+```
 
 [armhf-gnu]: https://github.com/rust-lang/rust/tree/master/src/ci/docker/host-x86_64/armhf-gnu/Dockerfile
 [QEMU]: https://www.qemu.org/