diff --git a/binary_c-config b/binary_c-config
index 4cbe9a974b7ea3578483533a1e1f02c2acca00b4..047201f8221c1e7de38dcc8f8673d52f4a81d1e8 100755
--- a/binary_c-config
+++ b/binary_c-config
@@ -106,7 +106,7 @@ while (( $# )); do
     case $key in
         --flags|-flags|flags|--cflags|-cflags|cflags)
             # return build flags
-            $VER 2>/dev/null | $GREP 'CFLAGS is \"' | $SED -e s/CFLAGS\ is\ // -e 's/^"[[:space:]]*//' -e 's/"[[:space:]]*$//'
+            $VER 2>/dev/null | $GREP 'CFLAGS is \"' | $SED -e s/CFLAGS\ is\ // -e 's/^"[[:space:]]*//' -e 's/"[[:space:]]*$//' #-e 's#$# -L/home/izzard/progs/stars/binary_c/src -I/home/izzard/progs/stars/binary_c/src#'
             shift
             ;;
         --define_macros|-define_macros|define_macros)
@@ -136,7 +136,7 @@ while (( $# )); do
             ;;
         --libs|-libs|libs) 
             # show libraries
-            $VER 2>/dev/null | $GREP 'LIBS is \"' | $SED -e s/LIBS\ is\ //  -e 's/-L[^[:space:]]*//g' -e 's/^"[[:space:]]*//' -e 's/"[[:space:]]*$//' -e 's/[[:space:]]\+/ /g' 
+            $VER 2>/dev/null | $GREP 'LIBS is \"' | $SED -e s/LIBS\ is\ //  -e 's/-L[^[:space:]]*//g' -e 's/^"[[:space:]]*//' -e 's/"[[:space:]]*$//' -e 's/[[:space:]]\+/ /g'
             shift
             ;;
         --libs_list|-libs_list|libs_list) 
diff --git a/meson.build b/meson.build
index 6f255f2559515c14d3f294511402de37faae0ca0..5ddbb9173f000c3a44ccd77309f0a4e509ba4e04 100644
--- a/meson.build
+++ b/meson.build
@@ -64,6 +64,7 @@ message('Meson process ID ' + pid)
 # paths in it (using the make_compile_commands_json.sh
 # script)
 #
+
 run_command('/bin/bash',
             'meson/background.sh',
             'meson/wait_for_exit.sh',
@@ -363,6 +364,7 @@ _other_cflags = [
     '-Wno-variadic-macros', # let these errors pass
     '-fstack-protector-all', # stack smashing checks (slows runtime)
     '-rdynamic',
+    '-fsignaling-nans', # probably required
 ]
 # clang-specific
 if compiler.get_id() == 'clang'
@@ -446,25 +448,33 @@ if get_option('accurate') == true
     ]
 else
     optional_flags += [
-        '-fno-associative-math',
+
+        ############################################################
         # these are what -ffast-math does without -funsafe-math-optimizations
+        #
+        # Note: we disable some of them
+        '-fno-associative-math',
         '-fno-math-errno',
-        '-ffinite-math-only',
+        #'-ffinite-math-only', # not good
         '-fno-rounding-math',
-        '-fno-signaling-nans',
+        #'-fno-signaling-nans', # should be off : nan-signalling is required
         '-fcx-limited-range',
         '-fexcess-precision=fast',
         # never allow unsafe math optimizations
         '-fno-unsafe-math-optimizations',
+        ############################################################
     ]
 endif
 
+# note:
+# -fno-finite-math-only and -fsignaling-nans cause
+# library-naming problems with gcc 10.3
+
 optional_flags += [
     '-fno-finite-math-only',
-    '-fsignaling-nans',
-    '-fomit-frame-pointer',
-    '-fvisibility=hidden',
     '-fasynchronous-unwind-tables',
+    '-fomit-frame-pointer', # not good for debugging?
+    '-fvisibility=hidden',
     '-rdynamic',
     '-export-dynamic',
 ]
@@ -1405,21 +1415,6 @@ cflags += [
   '-DMESON_PROJECT_VERSION=' + meson.project_version(),
 ]
 
-############################################################
-
-############################################################
-# command to make the compile_commands.json
-#
-if unix
-    compile_commands_json = [
-        '../meson/compile_commands.json'
-    ]
-else
-    compile_commands_json = [
-        'echo','"Cannot generate compile_commands.json on this operating system"'
-    ]
-endif
-
 ############################################################
 # make gtags database
 gtags = find_program('gtags',required:false)
@@ -1454,12 +1449,20 @@ if unix
         '&&',
         '../meson/list_shared_symbols.sh',libname,
     ]
+
+    # and show the version number after the build
+    # using binary_c-config (tests that this works)
+    binary_c_legacy_install_cmd += [
+        '&&',
+        'echo','-n','built binary_c ',
+        '&&',
+        '../binary_c-config','version',
+    ]
 else
     binary_c_legacy_install_cmd = [
         'echo','"Legacy install not supported on this operating system"'
         ]
 endif
-binary_c_legacy_install_cmd += compile_commands_json
 
 ############################################################
 #
@@ -1467,7 +1470,6 @@ binary_c_legacy_install_cmd += compile_commands_json
 # hence touch (and rebuild) it when the shared library is
 # rebuild
 #
-
 if os == 'linux' and \
    run_command('sh','-c','meson/check_binary_grid2.sh').returncode() == 0
     binary_grid2_file = run_command(
@@ -1644,7 +1646,14 @@ binary_c_shared_library = shared_library(
     ],
     link_args : [
         libs,
-        '-fvisibility=hidden',
+        #'-fvisibility=hidden',
+        # this fails '-Wl,-soname,libbinary_c',
+        #'-Wl,-soname,libbinary_c',
+
+        # this fails too
+        #'-Wl,-soname,libbinary_c.so',
+
+        #'-Wl,-export-dynamic',
     ],
     link_with: [
         binary_c_objects
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