[libc++] More documentation improvements about running tests
NOKEYCHECK=True
GitOrigin-RevId: 3d5d44269c933849068c073f356002940f85bce4
diff --git a/docs/TestingLibcxx.rst b/docs/TestingLibcxx.rst
index 25395f4..9d73b70 100644
--- a/docs/TestingLibcxx.rst
+++ b/docs/TestingLibcxx.rst
@@ -37,6 +37,12 @@
$ <build>/bin/llvm-lit -sv libcxx/test/std/depr/depr.c.headers/stdlib_h.pass.cpp # Run a single test
$ <build>/bin/llvm-lit -sv libcxx/test/std/atomics libcxx/test/std/threads # Test std::thread and std::atomic
+.. note::
+ If you used the Bootstrapping build instead of the default runtimes build, the
+ ``cxx-test-depends`` target is instead named ``runtimes-test-depends``, and
+ you will need to prefix ``<build>/runtimes/runtimes-<target>-bins/`` to the
+ paths of all tests.
+
In the default configuration, the tests are built against headers that form a
fake installation root of libc++. This installation root has to be updated when
changes are made to the headers, so you should re-run the ``cxx-test-depends``