"No support of nested C function" build failure(s) — clang 11.0.0

clang rejects inner functions while gcc accepts them.
void foo() {

     void bar() {

     }

}
PackageVersionSupposed error messageFull log Bug report
bluez 5.55-1profiles/midi/midi.c:79:75: error: function definition is not allowed here Log
bogl 0.1.18-15bogl-font.c:84:3: error: function definition is not allowed here Log 758063
growl-for-linux 0.8.5-8balloon.c:160:72: error: function definition is not allowed here Log
gst-plugins-espeak 0.5.0-1espeak.c:211:59: error: function definition is not allowed here Log
kraptor 0.0.20040403+ds-2src/game.c:416:3: error: function definition is not allowed here Log 750370
mandos 1.8.12-1plugins.d/password-prompt.c:119:51: error: function definition is not allowed here Log 750516
netplug 1.2.9.2-3if_info.c:295:37: error: function definition is not allowed here Log 750789
ratpoints 1:2.1.3-1./sturm.c:176:5: error: function definition is not allowed here Log
rsh-redone 85-2rlogin.c:388:30: error: function definition is not allowed here Log 750957
wtdbg2 2.5-7./wtdbg.h:1755:2: error: function definition is not allowed here Log

10 errors