diff --git a/.github/workflows/cmake-single-platform.yml b/.github/workflows/cmake-single-platform.yml
index b8f26927..527d5655 100644
--- a/.github/workflows/cmake-single-platform.yml
+++ b/.github/workflows/cmake-single-platform.yml
@@ -26,17 +26,34 @@ jobs:
       # install catch2.  see [[https://stackoverflow.com/questions/57982945/how-to-apt-get-install-in-a-github-actions-workflow]]
       run: sudo apt-get install -y catch2
 
+    # ----------------------------------------------------------------
+
+    - name: Clone xo-cmake
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-cmake
+        path: repo/xo-cmake
+
+    - name: Configure xo-cmake
+      run: cmake -B ${{github.workspace}}/build_xo-cmake -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/xo-cmake
+
+    - name: Build xo-cmake (trivial)
+      run: cmake --build ${{github.workspace}}/build_xo-cmake --config ${{env.BUILD_TYPE}}
+
+    - name: Install xo-cmake
+      run: cmake --install ${{github.workspace}}/build_xo-cmake
+
+    # ----------------------------------------------------------------
+
     - name: Clone indentlog
       uses: actions/checkout@v3
       with:
         repository: Rconybea/indentlog
         path: repo/indentlog
 
-
-
     - name: Configure indentlog
       # configure cmake for indentlog in dedicated build directory.
-      run: cmake -B ${{github.workspace}}/build_indentlog -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/indentlog
+      run: cmake -B ${{github.workspace}}/build_indentlog -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/indentlog
 
     - name: Build indentlog
       run: cmake --build ${{github.workspace}}/build_indentlog --config ${{env.BUILD_TYPE}}
@@ -45,12 +62,12 @@ jobs:
       # install into ${{github.workspace}}/local
       run: cmake --install ${{github.workspace}}/build_indentlog
 
+    # ----------------------------------------------------------------
 
-
-    - name: Configure refcnt
+    - name: Configure self (refcnt)
       # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
       # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
-      run: cmake -B ${{github.workspace}}/build_refcnt -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} --debug-find
+      run: cmake -B ${{github.workspace}}/build_refcnt -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
 
     - name: Build refcnt
       # Build your program with the given configuration
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0cdb52c..c360483c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,8 @@ cmake_minimum_required(VERSION 3.10)
 project(refcnt VERSION 0.1)
 enable_language(CXX)
 
+# common XO cmake macros (see proj/xo-cmake)
+include(xo_macros/xo_cxx)
 include(cmake/cxx.cmake)
 include(cmake/code-coverage.cmake)
 
diff --git a/README.md b/README.md
index 0835e7b9..bae1fb2c 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ Refcnt is a small shared library supplying intrusive reference counting.
 
 ### build + install `indentlog` dependency
 
-see [github/rconybea/indentlog](https://github.com/Rconybea/indentlog)
+see [github/Rconybea/indentlog](https://github.com/Rconybea/indentlog)
 
 ### copy `refcnt` repository locally
 ```
@@ -26,11 +26,13 @@ refcnt
 $ cd refcnt
 $ mkdir build
 $ cd build
-$ cmake -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} ..
+$ cmake -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake  -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} ..
 $ make
 $ make install
 ```
 
+`CMAKE_PREFIX_PATH` should point to prefix where `indentlog` is installed
+
 alternatively,  if you're a nix user:
 ```
 $ git clone git@github.com:rconybea/xo-nix.git
@@ -40,6 +42,14 @@ $ cd xo-nix
 $ nix-build -A refcnt
 ```
 
+### build for unit test coverage
+```
+$ cd refcnt
+$ mkdir ccov
+$ cd ccov
+$ cmake -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake  -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCODE_COVERAGE=ON -DCMAKE_BUILD_TYPE=Debug ..
+```
+
 ## Examples
 
 ### 1