While building the current master (8cf19fd), I get a lot of warnings like:
[ 191s] /home/abuild/rpmbuild/BUILD/FreeRDP-master/channels/client/tables.c:30:13: warning: type of 'disp_DVCPluginEntry' does not match original declaration [-Wlto-type-mismatch]
[ 191s] 30 | extern UINT disp_DVCPluginEntry(void);
[ 191s] | ^
[ 191s] /home/abuild/rpmbuild/BUILD/FreeRDP-master/channels/disp/client/disp_main.c:359:6: note: type mismatch in parameter 1
[ 191s] 359 | UINT DVCPluginEntry(IDRDYNVC_ENTRY_POINTS* pEntryPoints)
[ 191s] | ^
[ 191s] /home/abuild/rpmbuild/BUILD/FreeRDP-master/channels/disp/client/disp_main.c:359:6: note: 'disp_DVCPluginEntry' was previously declared here

I build with:
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_INSTALL_LIBDIR:PATH=lib64 -DCMAKE_SKIP_INSTALL_RPATH=ON -DWITH_CUPS=ON -DWITH_CLIENT=ON -DWITH_PCSC=ON -DWITH_ALSA=ON -DWITH_PULSE=ON -DWITH_OSS=OFF -DWITH_DIRECTFB=OFF -DWITH_JPEG=ON -DWITH_GSM=ON -DWITH_GSTREAMER_1_0=ON -DWITH_IPP=OFF -DWITH_OPENSSL=ON -DWITH_CHANNELS=ON -DWITH_X11=ON -DWITH_XCURSOR=ON -DWITH_XEXT=ON -DWITH_XKBFILE=ON -DWITH_XI=ON -DWITH_XINERAMA=ON -DWITH_XRENDER=ON -DWITH_XV=ON -DWITH_ZLIB=ON -DWITH_KRB5=ON -DBUILTIN_CHANNELS=ON -DWITH_SERVER=ON -DWITH_SSE2=ON -DWITH_DEBUG_SCARD=OFF -DWITH_SMARTCARD_INSPECT=ON -DWITH_ICU=ON -DWITH_FFMPEG=ON -DWITH_DSP_FFMPEG=ON -DWITH_WAYLAND=ON -DWITH_SANITIZE_ADDRESS=OFF -DWITH_LIBSYSTEMD=ON -DCMAKE_NO_BUILTIN_CHRPATH=ON -DWITH_LAME=ON -DWITH_CAIRO=ON .

In the attached file all warnings are listed.
osTWbuild_lto3.log.gz