diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9447bda..17ce39b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,6 +41,7 @@
 add_subdirectory(pw_kvs EXCLUDE_FROM_ALL)
 add_subdirectory(pw_log EXCLUDE_FROM_ALL)
 add_subdirectory(pw_log_basic EXCLUDE_FROM_ALL)
+add_subdirectory(pw_log_null EXCLUDE_FROM_ALL)
 add_subdirectory(pw_log_tokenized EXCLUDE_FROM_ALL)
 add_subdirectory(pw_minimal_cpp_stdlib EXCLUDE_FROM_ALL)
 add_subdirectory(pw_polyfill EXCLUDE_FROM_ALL)
diff --git a/pw_build/docs.rst b/pw_build/docs.rst
index a5d38da..c974828 100644
--- a/pw_build/docs.rst
+++ b/pw_build/docs.rst
@@ -399,8 +399,8 @@
   ├── file1.txt
   └── renamed.txt
 
-CMake / Ninja
-=============
+CMake
+=====
 Pigweed's `CMake`_ support is provided primarily for projects that have an
 existing CMake build and wish to integrate Pigweed without switching to a new
 build system.
diff --git a/pw_build/pigweed.cmake b/pw_build/pigweed.cmake
index 2d0fa3f..a004cd4 100644
--- a/pw_build/pigweed.cmake
+++ b/pw_build/pigweed.cmake
@@ -219,7 +219,12 @@
   # instead. If the facade is used in the build, it fails with this error.
   add_custom_target("${NAME}._no_backend_set_message"
     COMMAND
-      python "$ENV{PW_ROOT}/pw_build/py/pw_build/null_backend.py" "${NAME}"
+      "${CMAKE_COMMAND}" -E echo
+        "ERROR: Attempted to build the ${NAME} facade with no backend."
+        "Configure the ${NAME} backend using pw_set_backend or remove all dependencies on it."
+        "See https://pigweed.dev/pw_build."
+    COMMAND
+      "${CMAKE_COMMAND}" -E false
   )
   add_library("${NAME}.NO_BACKEND_SET" INTERFACE)
   add_dependencies("${NAME}.NO_BACKEND_SET" "${NAME}._no_backend_set_message")
diff --git a/pw_protobuf_compiler/proto.cmake b/pw_protobuf_compiler/proto.cmake
index 2410c5d..b7a4643 100644
--- a/pw_protobuf_compiler/proto.cmake
+++ b/pw_protobuf_compiler/proto.cmake
@@ -223,12 +223,12 @@
 
   if("${dir_pw_third_party_nanopb}" STREQUAL "")
     add_custom_target("${NAME}._generate.nanopb"
-        cmake -E echo
+        "${CMAKE_COMMAND}" -E echo
             ERROR: Attempting to use pw_proto_library, but
             dir_pw_third_party_nanopb is not set. Set dir_pw_third_party_nanopb
             to the path to the Nanopb repository.
       COMMAND
-        cmake -E false
+        "${CMAKE_COMMAND}" -E false
       DEPENDS
         ${DEPS}
       SOURCES