diff --git a/CMakeLists.txt b/CMakeLists.txt
index 70d41428d8..845aaf656d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -994,10 +994,6 @@ if(USE_PREBUILT_QTWEBKIT_PACKAGE)
             add_definitions(-DENABLE_TEST_PLUGINS)
         endif()
 
-        # Let OpenCOR know that we want Python support
-
-        add_definitions(-DPYTHON_SUPPORT)
-
         # Let OpenCOR know about the prebuilt version of our QtWebKit package
         # being used
 
@@ -1023,6 +1019,18 @@ if(USE_PREBUILT_QTWEBKIT_PACKAGE)
     endforeach()
 endif()
 
+# Keep track of whether we are building OpenCOR with Python support and, if so,
+# let OpenCOR know about it
+
+if(NOT "${PYTHON_SCRIPT_DIR}" STREQUAL "")
+    set(PYTHON_SUPPORT TRUE)
+
+    add_definitions(-DPYTHON_SUPPORT)
+
+    string(REPLACE "${PROJECT_BUILD_DIR}/" ""
+           RELATIVE_PYTHON_SCRIPT_DIR "${PYTHON_SCRIPT_DIR}")
+endif()
+
 # Fetch parts of our documentation and build it, if we are neither building
 # Python nor QtWebKit
 # Note: we need Python because we rely on Sphinx to build our documentation...
@@ -1085,7 +1093,7 @@ endif()
 # Note: this is because the lookup scope changes for DSOs that are loaded using
 #       dlopen() (see https://www.akkadia.org/drepper/dsohowto.pdf)...
 
-if(NOT WIN32 AND NOT APPLE)
+if(NOT WIN32 AND NOT APPLE AND PYTHON_SUPPORT)
     include_directories(${PYTHON_INCLUDE_DIR})
 
     target_link_libraries(${CMAKE_PROJECT_NAME}
@@ -1279,9 +1287,6 @@ else()
     set(CPACK_PACKAGE_VERSION_PATCH "${PROJECT_VERSION_PATCH}")
 endif()
 
-string(REPLACE "${PROJECT_BUILD_DIR}/" ""
-       RELATIVE_PYTHON_SCRIPT_DIR "${PYTHON_SCRIPT_DIR}")
-
 if(WIN32)
     # Select NSIS, if available, and ZIP as the packagers on Windows
 
@@ -1364,37 +1369,39 @@ if(WIN32)
     #       skip them in that case (see
     #       https://github.com/opencor/opencor/issues/1255#issuecomment-550605710)...
 
-    if(RELEASE_MODE)
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} runjupyter.bat)
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} start_jupyter.py)
-
-        install(FILES ${PLATFORM_DISTRIB_DIR}/runjupyter.bat
-                      ${PLATFORM_DISTRIB_DIR}/start_jupyter.py
-                DESTINATION ${RELATIVE_PYTHON_SCRIPT_DIR})
+    if(PYTHON_SUPPORT)
+        if(RELEASE_MODE)
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} runjupyter.bat)
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} start_jupyter.py)
+
+            install(FILES ${PLATFORM_DISTRIB_DIR}/runjupyter.bat
+                          ${PLATFORM_DISTRIB_DIR}/start_jupyter.py
+                    DESTINATION ${RELATIVE_PYTHON_SCRIPT_DIR})
+
+            set(JUPYTER_CONSOLE_FILENAME "${PROJECT_BUILD_DIR}/jupyterconsole.bat")
+
+            configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.bat.in ${JUPYTER_CONSOLE_FILENAME})
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab.bat)
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab.vbs)
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook.bat)
+            copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook.vbs)
+
+            install(FILES ${JUPYTER_CONSOLE_FILENAME}
+                          ${PLATFORM_DISTRIB_DIR}/jupyterlab.bat
+                          ${PLATFORM_DISTRIB_DIR}/jupyterlab.vbs
+                          ${PLATFORM_DISTRIB_DIR}/jupyternotebook.bat
+                          ${PLATFORM_DISTRIB_DIR}/jupyternotebook.vbs
+                    DESTINATION .)
+        endif()
 
-        set(JUPYTER_CONSOLE_FILENAME "${PROJECT_BUILD_DIR}/jupyterconsole.bat")
+        set(PYTHON_SHELL_FILENAME "${PROJECT_BUILD_DIR}/pythonshell.bat")
 
-        configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.bat.in ${JUPYTER_CONSOLE_FILENAME})
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab.bat)
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab.vbs)
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook.bat)
-        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook.vbs)
+        configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.bat.in ${PYTHON_SHELL_FILENAME})
 
-        install(FILES ${JUPYTER_CONSOLE_FILENAME}
-                      ${PLATFORM_DISTRIB_DIR}/jupyterlab.bat
-                      ${PLATFORM_DISTRIB_DIR}/jupyterlab.vbs
-                      ${PLATFORM_DISTRIB_DIR}/jupyternotebook.bat
-                      ${PLATFORM_DISTRIB_DIR}/jupyternotebook.vbs
+        install(FILES ${PYTHON_SHELL_FILENAME}
                 DESTINATION .)
     endif()
 
-    set(PYTHON_SHELL_FILENAME "${PROJECT_BUILD_DIR}/pythonshell.bat")
-
-    configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.bat.in ${PYTHON_SHELL_FILENAME})
-
-    install(FILES ${PYTHON_SHELL_FILENAME}
-            DESTINATION .)
-
     # File type association
     # Note: the calls to SHChangeNotify are to ensure that Windows refreshes
     #       file icons (so that it is clear to the user that an extension has
@@ -1444,26 +1451,28 @@ elseif(APPLE)
 
     # Shell scripts to setup and run Python and Jupyter
 
-    set(RUN_JUPYTER_FILENAME ${PYTHON_SCRIPT_DIR}/runjupyter)
+    if(PYTHON_SUPPORT)
+        set(RUN_JUPYTER_FILENAME ${PYTHON_SCRIPT_DIR}/runjupyter)
 
-    configure_file(${PLATFORM_DISTRIB_DIR}/runjupyter.in ${RUN_JUPYTER_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/runjupyter.in ${RUN_JUPYTER_FILENAME} @ONLY)
 
-    set(JUPYTER_CONSOLE_FILENAME ${PROJECT_BUILD_DIR}/jupyterconsole)
-    set(JUPYTER_LAB_FILENAME ${PROJECT_BUILD_DIR}/jupyterlab)
-    set(JUPYTER_NOTEBOOK_FILENAME ${PROJECT_BUILD_DIR}/jupyternotebook)
-    set(PYTHON_SHELL_FILENAME ${PROJECT_BUILD_DIR}/pythonshell)
+        set(JUPYTER_CONSOLE_FILENAME ${PROJECT_BUILD_DIR}/jupyterconsole)
+        set(JUPYTER_LAB_FILENAME ${PROJECT_BUILD_DIR}/jupyterlab)
+        set(JUPYTER_NOTEBOOK_FILENAME ${PROJECT_BUILD_DIR}/jupyternotebook)
+        set(PYTHON_SHELL_FILENAME ${PROJECT_BUILD_DIR}/pythonshell)
 
-    configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.in ${JUPYTER_CONSOLE_FILENAME} @ONLY)
-    configure_file(${PLATFORM_DISTRIB_DIR}/jupyterlab.in ${JUPYTER_LAB_FILENAME} @ONLY)
-    configure_file(${PLATFORM_DISTRIB_DIR}/jupyternotebook.in ${JUPYTER_NOTEBOOK_FILENAME} @ONLY)
-    configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.in ${PYTHON_SHELL_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.in ${JUPYTER_CONSOLE_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/jupyterlab.in ${JUPYTER_LAB_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/jupyternotebook.in ${JUPYTER_NOTEBOOK_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.in ${PYTHON_SHELL_FILENAME} @ONLY)
 
-    install(FILES ${JUPYTER_CONSOLE_FILENAME}
-                  ${JUPYTER_LAB_FILENAME}
-                  ${JUPYTER_NOTEBOOK_FILENAME}
-                  ${PYTHON_SHELL_FILENAME}
-            DESTINATION .
-            PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
+        install(FILES ${JUPYTER_CONSOLE_FILENAME}
+                      ${JUPYTER_LAB_FILENAME}
+                      ${JUPYTER_NOTEBOOK_FILENAME}
+                      ${PYTHON_SHELL_FILENAME}
+                DESTINATION .
+                PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
+    endif()
 else()
     # Select TGZ as the packager on Linux
 
@@ -1538,26 +1547,28 @@ else()
 
     # Shell scripts to setup and run Python and Jupyter
 
-    copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} runjupyter)
+    if(PYTHON_SUPPORT)
+        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} ${RELATIVE_PYTHON_SCRIPT_DIR} runjupyter)
 
-    install(FILES ${PLATFORM_DISTRIB_DIR}/runjupyter
-            DESTINATION ${RELATIVE_PYTHON_SCRIPT_DIR}
-            PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
+        install(FILES ${PLATFORM_DISTRIB_DIR}/runjupyter
+                DESTINATION ${RELATIVE_PYTHON_SCRIPT_DIR}
+                PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
 
-    set(JUPYTER_CONSOLE_FILENAME ${PROJECT_BUILD_DIR}/jupyterconsole)
-    set(PYTHON_SHELL_FILENAME ${PROJECT_BUILD_DIR}/pythonshell)
+        set(JUPYTER_CONSOLE_FILENAME ${PROJECT_BUILD_DIR}/jupyterconsole)
+        set(PYTHON_SHELL_FILENAME ${PROJECT_BUILD_DIR}/pythonshell)
 
-    configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.in ${JUPYTER_CONSOLE_FILENAME} @ONLY)
-    copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab)
-    copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook)
-    configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.in ${PYTHON_SHELL_FILENAME} @ONLY)
+        configure_file(${PLATFORM_DISTRIB_DIR}/jupyterconsole.in ${JUPYTER_CONSOLE_FILENAME} @ONLY)
+        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyterlab)
+        copy_file_to_build_dir(DIRECT ${PLATFORM_DISTRIB_DIR} . jupyternotebook)
+        configure_file(${PLATFORM_DISTRIB_DIR}/pythonshell.in ${PYTHON_SHELL_FILENAME} @ONLY)
 
-    install(FILES ${JUPYTER_CONSOLE_FILENAME}
-                  ${PLATFORM_DISTRIB_DIR}/jupyterlab
-                  ${PLATFORM_DISTRIB_DIR}/jupyternotebook
-                  ${PYTHON_SHELL_FILENAME}
-            DESTINATION .
-            PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
+        install(FILES ${JUPYTER_CONSOLE_FILENAME}
+                      ${PLATFORM_DISTRIB_DIR}/jupyterlab
+                      ${PLATFORM_DISTRIB_DIR}/jupyternotebook
+                      ${PYTHON_SHELL_FILENAME}
+                DESTINATION .
+                PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
+    endif()
 endif()
 
 # Specify the package file name, depending on whether we are generating a
diff --git a/distrib/linux/mesa/CMakeLists.txt b/distrib/linux/mesa/CMakeLists.txt
index d84069b273..c33fcf23ec 100644
--- a/distrib/linux/mesa/CMakeLists.txt
+++ b/distrib/linux/mesa/CMakeLists.txt
@@ -3,11 +3,11 @@ project(Mesa)
 # Name and version of our package
 
 set(PACKAGE_NAME Mesa)
-set(PACKAGE_VERSION 19.2.1)
+set(PACKAGE_VERSION 19.2.6)
 
 # Git tag for our library
 
-set(GIT_TAG v19.2.1)
+set(GIT_TAG v19.2.6)
 
 # Specify where our local package will be installed
 
@@ -30,9 +30,9 @@ if(USE_PREBUILT_MESA_PACKAGE)
     # Retrieve the library's package
 
     retrieve_package_file(${PACKAGE_NAME} ${PACKAGE_VERSION}
-                          ${FULL_LOCAL_EXTERNAL_PACKAGE_DIR} 33424e212f7f31f046041a6950d8b64fa8599346
+                          ${FULL_LOCAL_EXTERNAL_PACKAGE_DIR} 0943cd1413a302c943d6e613f44775ca216e8374
                           SHA1_FILES ${SHA1_FILES}
-                          SHA1_VALUES 3f90abfbe269daeb47909a2d4b728283e0f10479)
+                          SHA1_VALUES 6d8f2e89ef80e7f0f3fc4307e3b286a212664dd7)
 else()
     # Build Mesa as an external project
 
diff --git a/doc/downloads/index.js b/doc/downloads/index.js
index ebd6631840..e9f5b72aea 100644
--- a/doc/downloads/index.js
+++ b/doc/downloads/index.js
@@ -41,7 +41,7 @@ var jsonData = { "versions": [
                        { "change": "<strong>Python support:</strong> update the PATH using <code>\\</code> rather than <code>/</code> on Windows (see issue <a href=\"https://github.com/opencor/opencor/issues/2219\">#2219</a>)." },
                        { "change": "<strong>SED-ML support:</strong> added support left and right triangle symbols (see issue <a href=\"https://github.com/opencor/opencor/issues/2173\">#2173</a>)." },
                        { "change": "<strong>Simulation Experiment view:</strong> properly handle the Graph Panel properties (see issue <a href=\"https://github.com/opencor/opencor/issues/2171\">#2171</a>). Make sure that curves are plotted with all of their original settings when reloading a SED-ML file (see issue <a href=\"https://github.com/opencor/opencor/issues/2176\">#2176</a>). Make sure that all of a solver's properties get saved to a SED-ML file (see issue <a href=\"https://github.com/opencor/opencor/issues/2185\">#2185</a>)." },
-                       { "change": "<strong>Third-party libraries:</strong> upgraded the <a href=\"https://www.openssl.org/\">OpenSSL</a> library to version 1.1.1d (see issue <a href=\"https://github.com/opencor/opencor/issues/2157\">#2157</a>). Upgraded <a href=\"http://www.llvm.org/\">LLVM</a>+<a href=\"http://clang.llvm.org/\">Clang</a> to version 9.0.0 (see issue <a href=\"https://github.com/opencor/opencor/issues/2161\">#2161</a>). Upgraded <a href=\"https://www.mesa3d.org/\">Mesa</a> to version 19.2.1 (see issue <a href=\"https://github.com/opencor/opencor/issues/2197\">#2197</a>). Upgraded the <a href=\"http://computation.llnl.gov/projects/sundials\">SUNDIALS</a> library to version 5.0.0 (see issue <a href=\"https://github.com/opencor/opencor/issues/2198\">#2198</a>). Upgraded <a href=\"https://riverbankcomputing.com/software/qscintilla/intro\">QScintilla</a> to version 2.11.3 (see issue <a href=\"https://github.com/opencor/opencor/issues/2208\">#2208</a>)." }
+                       { "change": "<strong>Third-party libraries:</strong> upgraded the <a href=\"https://www.openssl.org/\">OpenSSL</a> library to version 1.1.1d (see issue <a href=\"https://github.com/opencor/opencor/issues/2157\">#2157</a>). Upgraded <a href=\"http://www.llvm.org/\">LLVM</a>+<a href=\"http://clang.llvm.org/\">Clang</a> to version 9.0.0 (see issue <a href=\"https://github.com/opencor/opencor/issues/2161\">#2161</a>). Upgraded the <a href=\"http://computation.llnl.gov/projects/sundials\">SUNDIALS</a> library to version 5.0.0 (see issue <a href=\"https://github.com/opencor/opencor/issues/2198\">#2198</a>). Upgraded <a href=\"https://riverbankcomputing.com/software/qscintilla/intro\">QScintilla</a> to version 2.11.3 (see issue <a href=\"https://github.com/opencor/opencor/issues/2208\">#2208</a>). Upgraded <a href=\"https://www.mesa3d.org/\">Mesa</a> to version 19.2.6 (see issue <a href=\"https://github.com/opencor/opencor/issues/2230\">#2230</a>)." }
                      ]
                    },
                    { "major": 0, "minor": 5, "patch": 0, "day": 15, "month": 10, "year": 2016, "type": 0, "license": 1,
diff --git a/src/main.cpp b/src/main.cpp
index 907776ef17..3b3d8ee10b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -25,7 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 //==============================================================================
 
-#ifdef Q_OS_LINUX
+#if defined(PYTHON_SUPPORT) && defined(Q_OS_LINUX)
     #include "Python.h"
     // Note: this needs to be included before <QObject> to prevent name clashes...
 #endif
@@ -72,7 +72,7 @@ int main(int pArgC, char *pArgV[])
     //       using dlopen() (see
     //       https://www.akkadia.org/drepper/dsohowto.pdf)...
 
-#ifdef Q_OS_LINUX
+#if defined(PYTHON_SUPPORT) && defined(Q_OS_LINUX)
     Py_NoUserSiteDirectory = 1;
 #endif
 
diff --git a/src/plugins/thirdParty/Python/CMakeLists.txt b/src/plugins/thirdParty/Python/CMakeLists.txt
index 8ff3666945..6aa4e77d45 100644
--- a/src/plugins/thirdParty/Python/CMakeLists.txt
+++ b/src/plugins/thirdParty/Python/CMakeLists.txt
@@ -459,7 +459,7 @@ set(PYTHON_LIBRARY ${ROOT_DIR}/${LIBRARY_DIR}/${IMPORT_LIBRARY} PARENT_SCOPE)
 set(PYTHON_EXECUTABLE ${ROOT_DIR}/${PYTHON_EXECUTABLE} PARENT_SCOPE)
 
 set(PYTHON_RELATIVE_SCRIPT_DIR ${SCRIPT_DIR} PARENT_SCOPE)
-set(PYTHON_SCRIPT_DIR  ${ROOT_DIR}/${SCRIPT_DIR} PARENT_SCOPE)
+set(PYTHON_SCRIPT_DIR ${ROOT_DIR}/${SCRIPT_DIR} PARENT_SCOPE)
 
 set(PYTHON_RELATIVE_RUNTIME_DIR ${RUNTIME_DIR} PARENT_SCOPE)