diff -r 6960d25eb0ba -r db21aab20169 configure
--- a/configure	Wed May 07 23:59:13 2025 +0200
+++ b/configure	Tue Nov 04 22:28:58 2025 +0100
@@ -58,6 +58,7 @@
 # $PLATFORM is used for platform dependent dependency selection
 OS=`uname -s`
 OS_VERSION=`uname -r`
+ARCH=`uname -m`
 printf "detect platform... "
 if [ "$OS" = "SunOS" ]; then
     PLATFORM="solaris sunos unix svr4"
@@ -229,6 +230,28 @@
     printf "loading site defaults... "
     . "$prefix/etc/config.site"
     echo ok
+else
+    # try to detect the correct libdir on our own, except it was changed by the user
+    if test "$libdir" = '${exec_prefix}/lib'; then
+        if [ "$OS" = "SunOS" ]; then
+            test -d "${exec_prefix}/lib/amd64" && libdir='${exec_prefix}/lib/amd64'
+        else
+            # check if the standard libdir even exists
+            if test -d "${exec_prefix}/lib" ; then
+                :
+            else
+                # if it does not, maybe a lib32 exists
+                test -d "${exec_prefix}/lib32" && libdir='${exec_prefix}/lib32'
+            fi
+            # now check if there is a special 64bit libdir that we should use
+            for i in x86_64 ppc64 s390x aarch64 aarch64_be arm64 ; do
+                if [ $ARCH = $i ]; then
+                    test -d "${exec_prefix}/lib64" && libdir='${exec_prefix}/lib64'
+                    break
+                fi
+            done
+        fi
+    fi
 fi
 
 
@@ -316,12 +339,12 @@
 
 # build type
 if [ "$BUILD_TYPE" = "debug" ]; then
-    TEMP_CFLAGS="\${DEBUG_CFLAGS}$TEMP_CFLAGS"
-    TEMP_CXXFLAGS="\${DEBUG_CXXFLAGS}$TEMP_CXXFLAGS"
+    TEMP_CFLAGS="\${DEBUG_CFLAGS} $TEMP_CFLAGS"
+    TEMP_CXXFLAGS="\${DEBUG_CXXFLAGS} $TEMP_CXXFLAGS"
 fi
 if [ "$BUILD_TYPE" = "release" ]; then
-    TEMP_CFLAGS="\${RELEASE_CFLAGS}$TEMP_CFLAGS"
-    TEMP_CXXFLAGS="\${RELEASE_CXXFLAGS}$TEMP_CXXFLAGS"
+    TEMP_CFLAGS="\${RELEASE_CFLAGS} $TEMP_CFLAGS"
+    TEMP_CXXFLAGS="\${RELEASE_CXXFLAGS} $TEMP_CXXFLAGS"
 fi
 
 # add general dependency flags to flags.mk