compiler crash for 2.0.16 (linux 20.04)

I got the latest source code and followed the build instruction.

Some libraries are generated properly, but at linking time for the sfScope64r I regularly get the following error:

xxx:/virtual/scopefun/ScopeFun-2.0.16-Source/build$ make package
[  5%] Built target Python2716
[ 11%] Built target wxWidgets304
[ 17%] Built target SDL2209
[ 22%] Built target libUsb1022
[ 23%] Linking CXX executable ../../bin/sfScope64r
/usr/bin/ld: ../../lib/SDL2-2.0.9/sfBuild64r/build/.libs/libSDL2.a(SDL_sndioaudio.o): in function `load_sndio_syms':
/virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:95: undefined reference to `sio_open'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:96: undefined reference to `sio_close'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:97: undefined reference to `sio_setpar'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:98: undefined reference to `sio_getpar'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:99: undefined reference to `sio_start'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:100: undefined reference to `sio_stop'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:101: undefined reference to `sio_read'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:102: undefined reference to `sio_write'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:103: undefined reference to `sio_nfds'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:104: undefined reference to `sio_pollfd'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:105: undefined reference to `sio_revents'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:106: undefined reference to `sio_eof'
/usr/bin/ld: /virtual/scopefun/ScopeFun-2.0.16-Source/lib/SDL2-2.0.9/src/audio/sndio/SDL_sndioaudio.c:107: undefined reference to `sio_initpar'
collect2: error: ld returned 1 exit status
make[2]: *** [source/CMakeFiles/sfScope.dir/build.make:1008: ../bin/sfScope64r] Fehler 1
make[1]: *** [CMakeFiles/Makefile2:252: source/CMakeFiles/sfScope.dir/all] Fehler 2
make: *** [Makefile:171: all] Fehler 2
My configuration:
Linux xxx 5.4.0-59-generic #65-Ubuntu SMP Thu Dec 10 12:01:51 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Some ideas how to proceed?

I have found a similar issue in stackoverflow... SDL_sndioaudio.c: undefined reference to `sio_*'
Could you try the recommended solution and report if it helps?

Thank you for your hint. It wasn't helpful in that way that it gives the solution. I'm quite new with the cmake tool and I'm learning a lot of pitfalls. The described error was overcome by installing the following package:

libglw1-mesa-dev

After that I stepped into the next problem:

make  -f source/CMakeFiles/sfScope.dir/build.make source/CMakeFiles/sfScope.dir/build
make[2]: Verzeichnis „/virtual/scopefun/ScopeFun-2.0.16-Source/build“ wird betreten
make[2]: *** Keine Regel vorhanden, um das Ziel „../lib/wxWidgets-3.0.4/sfBuild64r/lib/libwxjpeg-3.0.a“,
  benötigt von „../bin/sfScope64r“, zu erstellen.  Schluss.
make[2]: Verzeichnis „/virtual/scopefun/ScopeFun-2.0.16-Source/build“ wird verlassen
make[1]: *** [CMakeFiles/Makefile2:255: source/CMakeFiles/sfScope.dir/all] Fehler 2
make[1]: Verzeichnis „/virtual/scopefun/ScopeFun-2.0.16-Source/build“ wird verlassen
make: *** [Makefile:174: all] Fehler 2

A library "libwxjpeg" shall be linked, which is not build by the delivered wxWidged library but which is in the dependency list of the generated Makefile for sfApi, SfScope and SfServer. I didn't found the generation mechanism by now, some help would be appreciated. Is there a tool for graphical visualtization of the dependencies?

update:

I found this topic for the wxWidgets Libraries:
[https://www.scopefun.com/smf/index.php?topic=79.msg269#msg269]

After applying this solution the original problem came back.  It could be solved in the same manner:

in the same list theSDIO-library has to be added. I put as last line "sndio".

The compilation of the package was the successful.