diff --git a/.github/workflows/build-macos.yml b/.github/workflows/build-macos.yml
index 462723222..7b7646328 100644
--- a/.github/workflows/build-macos.yml
+++ b/.github/workflows/build-macos.yml
@@ -19,16 +19,16 @@ jobs:
         # Github Actions requires a single row to be added to the build matrix.
         # See https://help.github.com/en/articles/workflow-syntax-for-github-actions.
         name: [
-          macOS-10.15-xcode-11.3.1,
+          macos-11-xcode-13.4.1,
         ]
 
         build_type: [Debug, Release]
         build_unstable: [ON]
         include:
-          - name: macOS-10.15-xcode-11.3.1
-            os: macOS-10.15
+          - name: macos-11-xcode-13.4.1
+            os: macos-11
             compiler: xcode
-            version: "11.3.1"
+            version: "13.4.1"
 
     steps:
       - name: Checkout
@@ -43,7 +43,7 @@ jobs:
             echo "CC=gcc-${{ matrix.version }}" >> $GITHUB_ENV
             echo "CXX=g++-${{ matrix.version }}" >> $GITHUB_ENV
           else
-            sudo xcode-select -switch /Applications/Xcode_${{ matrix.version }}.app
+            sudo xcode-select -switch /Applications/Xcode.app
             echo "CC=clang" >> $GITHUB_ENV
             echo "CXX=clang++" >> $GITHUB_ENV
           fi
diff --git a/.github/workflows/build-python.yml b/.github/workflows/build-python.yml
index 3fc2d662f..f80b9362c 100644
--- a/.github/workflows/build-python.yml
+++ b/.github/workflows/build-python.yml
@@ -22,7 +22,7 @@ jobs:
           ubuntu-18.04-gcc-5,
           ubuntu-18.04-gcc-9,
           ubuntu-18.04-clang-9,
-          macOS-10.15-xcode-11.3.1,
+          macOS-11-xcode-13.4.1,
           ubuntu-18.04-gcc-5-tbb,
         ]
 
@@ -52,10 +52,10 @@ jobs:
             build_type: Debug
             python_version: "3"
 
-          - name: macOS-10.15-xcode-11.3.1
-            os: macOS-10.15
+          - name: macOS-11-xcode-13.4.1
+            os: macOS-11
             compiler: xcode
-            version: "11.3.1"
+            version: "13.4.1"
 
           - name: ubuntu-18.04-gcc-5-tbb
             os: ubuntu-18.04
@@ -103,7 +103,7 @@ jobs:
             echo "CC=gcc-${{ matrix.version }}" >> $GITHUB_ENV
             echo "CXX=g++-${{ matrix.version }}" >> $GITHUB_ENV
           else
-            sudo xcode-select -switch /Applications/Xcode_${{ matrix.version }}.app
+            sudo xcode-select -switch /Applications/Xcode.app
             echo "CC=clang" >> $GITHUB_ENV
             echo "CXX=clang++" >> $GITHUB_ENV
           fi
@@ -112,6 +112,11 @@ jobs:
         run: |
           echo "GTSAM_WITH_TBB=ON" >> $GITHUB_ENV
           echo "GTSAM Uses TBB"
+      - name: Set Swap Space
+        if: runner.os == 'Linux'
+        uses: pierotofy/set-swap-space@master
+        with:
+          swap-size-gb: 6
       - name: Build (Linux)
         if: runner.os == 'Linux'
         run: |
diff --git a/gtsam/base/ConcurrentMap.h b/gtsam/base/ConcurrentMap.h
index 2d7cbd6db..cf4537d4c 100644
--- a/gtsam/base/ConcurrentMap.h
+++ b/gtsam/base/ConcurrentMap.h
@@ -113,6 +113,7 @@ private:
   template<class Archive>
   void load(Archive& ar, const unsigned int /*version*/)
   {
+    this->clear();
     // Load into STL container and then fill our map
     FastVector<std::pair<KEY, VALUE> > map;
     ar & BOOST_SERIALIZATION_NVP(map);
diff --git a/gtsam/base/tests/testSerializationBase.cpp b/gtsam/base/tests/testSerializationBase.cpp
index f7aa97b31..d2f4d5f51 100644
--- a/gtsam/base/tests/testSerializationBase.cpp
+++ b/gtsam/base/tests/testSerializationBase.cpp
@@ -18,6 +18,7 @@
 
 #include <gtsam/inference/Key.h>
 
+#include <gtsam/base/ConcurrentMap.h>
 #include <gtsam/base/Matrix.h>
 #include <gtsam/base/MatrixSerialization.h>
 #include <gtsam/base/Vector.h>
@@ -106,6 +107,39 @@ TEST (Serialization, matrix_vector) {
   EXPECT(equalityBinary<Matrix>((Matrix(2, 2) << 1.0, 2.0, 3.0, 4.0).finished()));
 }
 
+/* ************************************************************************* */
+TEST (Serialization, ConcurrentMap) {
+
+  ConcurrentMap<int, std::string> map;
+
+  map.insert(make_pair(1, "apple"));
+  map.insert(make_pair(2, "banana"));
+
+  std::string binaryPath = "saved_map.dat";
+    try {
+    std::ofstream outputStream(binaryPath);
+    boost::archive::binary_oarchive outputArchive(outputStream);
+    outputArchive << map;
+  } catch(...) {
+    EXPECT(false);
+  }
+
+  // Verify that the existing map contents are replaced by the archive data
+  ConcurrentMap<int, std::string> mapFromDisk;
+  mapFromDisk.insert(make_pair(3, "clam"));
+  EXPECT(mapFromDisk.exists(3));
+  try {
+    std::ifstream ifs(binaryPath);
+    boost::archive::binary_iarchive inputArchive(ifs);
+    inputArchive >> mapFromDisk;
+  } catch(...) {
+    EXPECT(false);
+  }
+  EXPECT(mapFromDisk.exists(1));
+  EXPECT(mapFromDisk.exists(2));
+  EXPECT(!mapFromDisk.exists(3));
+}
+
 /* ************************************************************************* */
 
 
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 9d5ba3ea7..fde3e1d9a 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -87,7 +87,8 @@ copy_directory("${CMAKE_CURRENT_SOURCE_DIR}/gtsam"
 # Hack to get python test and util files copied every time they are modified
 file(GLOB GTSAM_PYTHON_TEST_FILES "${CMAKE_CURRENT_SOURCE_DIR}/gtsam/tests/*.py")
 foreach(test_file ${GTSAM_PYTHON_TEST_FILES})
-        configure_file(${test_file} "${GTSAM_MODULE_PATH}/tests/${test_file}" COPYONLY)
+        get_filename_component(test_file_name ${test_file} NAME)
+        configure_file(${test_file} "${GTSAM_MODULE_PATH}/tests/${test_file_name}" COPYONLY)
 endforeach()
 file(GLOB GTSAM_PYTHON_UTIL_FILES "${CMAKE_CURRENT_SOURCE_DIR}/gtsam/utils/*.py")
 foreach(util_file ${GTSAM_PYTHON_UTIL_FILES})