diff --git a/boost.sh b/boost.sh
index 2250c8e30b..8c2ba3f820 100644
--- a/boost.sh
+++ b/boost.sh
@@ -81,6 +81,7 @@ b2 -q                                                 \
    --disable-icu                                      \
    --without-context                                  \
    --without-coroutine                                \
+   --without-fiber                                    \
    --without-graph                                    \
    --without-graph_parallel                           \
    --without-locale                                   \
diff --git a/fairroot.sh b/fairroot.sh
index 45345f3818..a29627e357 100644
--- a/fairroot.sh
+++ b/fairroot.sh
@@ -21,6 +21,7 @@ incremental_recipe: |
   cmake $SOURCEDIR                          \
         -DCMAKE_GENERATOR=Ninja             \
         -DCMAKE_INSTALL_PREFIX=$INSTALLROOT \
+        -DCMAKE_POLICY_VERSION_MINIMUM=3.5  \
         -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
   cp ${BUILDDIR}/compile_commands.json ${INSTALLROOT}
   cmake --build . -- ${JOBS+-j $JOBS} install
@@ -75,6 +76,7 @@ cmake $SOURCEDIR
       ${CXXSTD:+-DCMAKE_CXX_STANDARD=$CXXSTD}                                               \
       -DCMAKE_DISABLE_FIND_PACKAGE_yaml-cpp=ON                                              \
       -DCMAKE_EXPORT_COMPILE_COMMANDS=ON                                                    \
+      -DCMAKE_POLICY_VERSION_MINIMUM=3.5                                                    \
       -DCMAKE_INSTALL_LIBDIR=lib                                                            \
       -DCMAKE_INSTALL_PREFIX=$INSTALLROOT
 
diff --git a/rapidjson.sh b/rapidjson.sh
index 3af1cb6414..f784d05248 100644
--- a/rapidjson.sh
+++ b/rapidjson.sh
@@ -14,6 +14,7 @@ cmake $SOURCEDIR                                                       \
       -G Ninja                                                         \
       -DCMAKE_INSTALL_PREFIX=$INSTALLROOT                              \
       -DCMAKE_POLICY_DEFAULT_CMP0077=NEW                               \
+      -DCMAKE_POLICY_VERSION_MINIMUM=3.5                               \
       -DRAPIDJSON_BUILD_TESTS=OFF                                      \
       -DRAPIDJSON_BUILD_EXAMPLES=OFF
 
diff --git a/root.sh b/root.sh
index 2e422033c1..30dd65c97b 100644
--- a/root.sh
+++ b/root.sh
@@ -103,8 +103,11 @@ fi
 # ROOT 6+: enable Python
 ROOT_PYTHON_FLAGS="-Dpyroot=ON"
 ROOT_HAS_PYTHON=1
-python_exec=$(python -c 'import distutils.sysconfig; print(distutils.sysconfig.get_config_var("exec_prefix"))')/bin/python3
-if [ "$python_exec" = "$(which python)" ]; then
+# Use python3 explicitly for compatibility with systems that don't have 'python' symlink
+PYTHON_CMD=$(which python3 2>/dev/null || which python 2>/dev/null || echo "python3")
+# Use sysconfig instead of distutils.sysconfig (distutils removed in Python 3.12+)
+python_exec=$($PYTHON_CMD -c 'import sysconfig; print(sysconfig.get_config_var("exec_prefix"))')/bin/python3
+if [ "$python_exec" = "$(which $PYTHON_CMD)" ]; then
   # By default, if there's nothing funny going on, let ROOT pick the Python in
   # the PATH, which is the one built by us (unless disabled, in which case it
   # is the system one). This is substituted into ROOT's Python scripts'
@@ -205,7 +208,7 @@ cmake --build . --target install ${JOBS+-j $JOBS}
 
 # Make sure ROOT actually found its build dependencies and didn't disable
 # features we requested. "-Dfail-on-missing=ON" would probably be better.
-[ "$("$INSTALLROOT/bin/root-config" --has-fftw3)" = yes ]
+[ "$("$INSTALLROOT/bin/root-config" --has-fftw3)" = yes ] || { echo "FFTW3 support required"; exit 1; }
 
 # Add support for ROOT_PLUGIN_PATH envvar for specifying additional plugin search paths
 grep -v '^Unix.*.Root.PluginPath' $INSTALLROOT/etc/system.rootrc > system.rootrc.0
@@ -231,8 +234,7 @@ rm -vf "$INSTALLROOT/etc/plugins/TGrid/P010_TAlien.C"         \
        "$INSTALLROOT/LICENSE"
 
 # Make sure all the tools use the correct python
-for binfile in "$INSTALLROOT"/bin/*; do
-  [ -f "$binfile" ] || continue
+for binfile in $(find "$INSTALLROOT"/bin -type f -exec grep -Iq . {} \; -print); do
   if grep -q "^'''exec' .*python.*" "$binfile"; then
     # This file uses a hack to get around shebang size limits. As we're
     # replacing the shebang with the system python, the limit doesn't apply and