[CM] newbie - how to build and run

[adam]

System is desktop Ubuntu 20.04 64-bit. 
snd-24.5.tar.gz unzipped to ~/Downloads/snd-24.5$ 
$ ./configure --with-pulseaudio 
$ make
---> 
  Options selected
  -------------------------
  Snd version ...........: 24.5
  CFLAGS ................: -O2 -I. -g -O2
  LDFLAGS ...............: -Wl,-export-dynamic
  LIBS...................:  -lm -ldl
  prefix.................: /usr/local
  extension language.....: s7
  audio system...........: pulseaudio
  graphics toolkit.......: None
  optional libraries.....: fftw-3.3.8
  random features........:
  environs...............: x86_64-pc-linux-gnu gcc
$ make install

$ snd ~/csound/test.wav 
writing libc_s7.c
loading libc_s7.so
<1> 


That's promising. Need graphics, so make clean and re-run with --with-gui 

$ make 
gcc -c -DSCRIPTS_DIR=\"/usr/local/share/snd\"  -O2 -I. -g -O2      s7.c
gcc -c -DSCRIPTS_DIR=\"/usr/local/share/snd\"  -O2 -I. -g -O2      headers.c
In file included from snd.h:35,
                 from headers.c:40:
snd-x0.h:4:10: fatal error: Xm/XmAll.h: No such file or directory
    4 | #include <Xm/XmAll.h>
      |          ^~~~~~~~~~~~
compilation terminated.
make: *** [makefile:55: headers.o] Error 1

Perhaps I need --with-motif in place of --with-gui ? What is motif I wonder.
With its associated libraries as outlined in README.Snd line 48 ?