diff --git a/cmake/BayeuxDependencies.cmake b/cmake/BayeuxDependencies.cmake
index 6f31339c2..472ca86e9 100644
--- a/cmake/BayeuxDependencies.cmake
+++ b/cmake/BayeuxDependencies.cmake
@@ -76,6 +76,8 @@ endif()
 if (Boost_VERSION VERSION_GREATER_EQUAL 107400)
   message(STATUS "Forcing BOOST_BIND_GLOBAL_PLACEHOLDERS...")
   add_definitions("-DBOOST_BIND_GLOBAL_PLACEHOLDERS")
+  # 2024-09-06 FM: disable for boost/spirit/include/phoenix_core.hpp and others...
+  add_definitions("-DBOOST_ALLOW_DEPRECATED_HEADERS")
 endif()
 
 foreach(_boost_lib ${BAYEUX_BOOST_COMPONENTS})
diff --git a/source/bxdatatools/testing/test_enriched_base.cxx b/source/bxdatatools/testing/test_enriched_base.cxx
index 094ebc2ba..66d54fd9a 100644
--- a/source/bxdatatools/testing/test_enriched_base.cxx
+++ b/source/bxdatatools/testing/test_enriched_base.cxx
@@ -17,6 +17,7 @@
 #include <datatools/enriched_base.h>
 
 #if DATATOOLS_WITH_REFLECTION == 1
+#include <datatools/detail/api.h> // for __GNUC_VERSION__
 // - Camp:
 #include <camp/userobject.hpp>
 #include <camp/value.hpp>
@@ -30,13 +31,6 @@ void test2();
 void test_reflection();
 #endif // DATATOOLS_WITH_REFLECTION == 1
 
-#if defined(__GNUG__)
-#pragma GCC   diagnostic ignored "-Werror=dangling-reference"
-#endif
-#if defined(__clang__)
-#pragma clang diagnostic ignored "-Werror=dangling-reference"
-#endif
-
 int main(int /* argc_ */, char ** /* argv_ */)
 {
   int error_code = EXIT_SUCCESS;
@@ -100,10 +94,28 @@ void test2()
 }
 
 #if DATATOOLS_WITH_REFLECTION == 1
+#if defined(__GNUG__)
+#if GCC_VERSION >= 13
+#pragma GCC diagnostic ignored "-Wdangling-reference"
+#endif
+#endif
 void test_reflection()
 {
   std::cerr << "\n******** Entering test_reflection... " << std::endl;
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
   const camp::Class & aoMetaClass = camp::classByName("datatools::enriched_base");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
   std::cerr << "******** Go. " << std::endl;
 
   camp::UserObject aoObj = aoMetaClass.construct();
diff --git a/source/bxdatatools/testing/test_handle_operators.cxx b/source/bxdatatools/testing/test_handle_operators.cxx
index 11e9326f5..fcbb29170 100644
--- a/source/bxdatatools/testing/test_handle_operators.cxx
+++ b/source/bxdatatools/testing/test_handle_operators.cxx
@@ -114,8 +114,12 @@ bool test_handle_deref_operator()
     x.reset();
     bool gotException{false};
     try {
-      auto sz = x->size();
-      std::clog << "sz=" << sz << '\n';
+#if defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-value"
+      x->size();
+#pragma GCC diagnostic pop
+#endif
     } catch (std::logic_error& e) {
       //o.k., we've caught the expected error
       gotException = true;
diff --git a/source/bxdatatools/testing/test_reflection_0.cxx b/source/bxdatatools/testing/test_reflection_0.cxx
index 427cb1f11..595aecba2 100644
--- a/source/bxdatatools/testing/test_reflection_0.cxx
+++ b/source/bxdatatools/testing/test_reflection_0.cxx
@@ -24,12 +24,13 @@
 #include <datatools/properties.h>
 #include <datatools/multi_properties.h>
 #include <datatools/things.h>
+#include <datatools/detail/api.h> // for __GNUC_VERSION__
 
-#if defined(__GNUG__)
-#pragma GCC   diagnostic ignored "-Werror=dangling-reference"
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+#pragma message "GCC13 workaround : applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic ignored "-Wdangling-reference"
 #endif
-#if defined(__clang__)
-#pragma clang diagnostic ignored "-Werror=dangling-reference"
 #endif
 
 void test_things(bool /*debug_*/);
@@ -92,7 +93,20 @@ void test_things (bool /*debug_*/)
   std::clog << "*** test_things : " << std::endl;
 
   // Access meta class for class 'things' :
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
   const camp::Class & tMetaClass = camp::classByName("datatools::things");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Restoring original diagnostic conditions"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
   {
 
     // Allocate a new 'things' object from the metaclass factory
@@ -155,7 +169,20 @@ void test_things (bool /*debug_*/)
 void test_multi_properties (bool /*debug_*/)
 {
   std::clog << "*** test_multi_properties : " << std::endl;
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
   const camp::Class & mpropsMetaClass = camp::classByName("datatools::multi_properties");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
   {
     camp::UserObject mpropsObj = mpropsMetaClass.construct(camp::Args ("id", "class"));
 
@@ -212,7 +239,20 @@ void test_multi_properties (bool /*debug_*/)
 void test_properties (bool /*debug_*/)
 {
   std::clog << "*** test_properties : " << std::endl;
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
   const camp::Class & propsMetaClass = camp::classByName("datatools::properties");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
 
   {
     //boost::scoped_ptr<datatools::properties> props (propsMetaClass.construct<datatools::properties> (camp::Args ("A test properties")));
@@ -256,7 +296,20 @@ void test_properties (bool /*debug_*/)
 void test_event_id (bool /*debug_*/)
 {
   std::clog << "*** test_event_id : " << std::endl;
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
   const camp::Class & evIdMetaClass = camp::classByName("datatools::event_id");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
 
   {
     //boost::scoped_ptr<datatools::event_id> evId (evIdMetaClass.construct<datatools::event_id> (camp::Args (3, 55)));
@@ -290,7 +343,20 @@ void test_logger (bool /*debug_*/)
 {
   std::clog << "*** test_logger : " << std::endl;
   {
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic push
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
     const camp::Class & tMetaClass = camp::classByName("datatools::logger");
+// #if defined(__GNUC__)
+// #if __GNUC_VERSION__ >= 130000
+//   // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+// #pragma GCC diagnostic pop
+// #endif
+// #endif
     std::clog << "tMetaClass = " << tMetaClass.name() <<  std::endl;
 
     try {
diff --git a/source/bxgenbb_help/programs/genbb_inspector.cxx b/source/bxgenbb_help/programs/genbb_inspector.cxx
index 77030a67f..4e9f62a23 100644
--- a/source/bxgenbb_help/programs/genbb_inspector.cxx
+++ b/source/bxgenbb_help/programs/genbb_inspector.cxx
@@ -89,12 +89,12 @@
 #include <genbb_help/primary_event.ipp>
 #include <genbb_help/version.h>
 #include <genbb_help/resource.h>
+#include <datatools/detail/api.h> // for __GNUC_VERSION__
 
 #if defined(__GNUG__)
-#pragma GCC   diagnostic ignored "-Werror=dangling-reference"
+#if GCC_VERSION >= 13
+#pragma GCC diagnostic ignored "-Wdangling-reference"
 #endif
-#if defined(__clang__)
-#pragma clang diagnostic ignored "-Werror=dangling-reference"
 #endif
 
 namespace dtc = datatools::configuration;
diff --git a/source/bxgenbb_help/testing/test_reflection_0.cxx b/source/bxgenbb_help/testing/test_reflection_0.cxx
index 74cf9d211..b58522a9b 100644
--- a/source/bxgenbb_help/testing/test_reflection_0.cxx
+++ b/source/bxgenbb_help/testing/test_reflection_0.cxx
@@ -18,11 +18,18 @@
 // - Bayeux/datatools:
 #include <datatools/logger.h>
 #include <datatools/clhep_units.h>
+#include <datatools/detail/api.h> // for __GNUC_VERSION__
 
 // Introspectable classes :
 #include <genbb_help/primary_particle.h>
 #include <genbb_help/primary_event.h>
 
+// #if defined(__GNUG__)
+// #if GCC_VERSION >= 13
+// #pragma GCC diagnostic ignored "-Wdangling-reference"
+// #endif
+// #endif
+
 void test_primary_particle();
 void test_primary_event();
 
@@ -61,7 +68,20 @@ int main (int /* argc_ */, char ** /* argv_ */)
 void test_primary_particle()
 {
   datatools::logger::priority logging = datatools::logger::PRIO_NOTICE;
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdangling-reference"
+#endif
+#endif
   const camp::Class & ppMetaClass  = camp::classByName("genbb::primary_particle");
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic pop
+#endif
+#endif
 
   camp::UserObject partObj0 = ppMetaClass.construct();
   DT_LOG_NOTICE(logging, "Initializing the primary particle object...");
@@ -87,7 +107,20 @@ void test_primary_particle()
 void test_primary_event()
 {
   //datatools::logger::priority logging = datatools::logger::PRIO_NOTICE;
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdangling-reference"
+#endif
+#endif
   const camp::Class & peMetaClass  = camp::classByName("genbb::primary_event");
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic pop
+#endif
+#endif
 
   camp::UserObject eventObj0 = peMetaClass.construct();
 
diff --git a/source/bxgeomtools/testing/test_reflection_0.cxx b/source/bxgeomtools/testing/test_reflection_0.cxx
index b726a5a2c..a1d52f939 100644
--- a/source/bxgeomtools/testing/test_reflection_0.cxx
+++ b/source/bxgeomtools/testing/test_reflection_0.cxx
@@ -22,6 +22,7 @@
 // - Bayeux/datatools:
 #include <datatools/logger.h>
 #include <datatools/clhep_units.h>
+#include <datatools/detail/api.h> // for __GNUC_VERSION__
 
 // Introspectable classes :
 #include <geomtools/utils.h>
@@ -29,11 +30,30 @@
 #include <geomtools/base_hit.h>
 #include <geomtools/placement.h>
 
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+#pragma message "GCC13 workaround : applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic ignored "-Wdangling-reference"
+#endif
+#endif
 
 void test_placement()
 {
   datatools::logger::priority logging = datatools::logger::PRIO_NOTICE;
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdangling-reference"
+#endif
+#endif
   const camp::Class & plctMetaClass  = camp::classByName("geomtools::placement");
+#if defined(__GNUC__)
+#if __GNUC_VERSION__ >= 130000
+  // #pragma message "Applying special diagnostic ignored '-Wdangling-reference'"
+#pragma GCC diagnostic pop
+#endif
+#endif
 
   camp::UserObject plctObj0 = plctMetaClass.construct();