NWZ Create UPG Fails

[majjam]

Hi
i want to create an altered bootloader for my sonyNWZe580 (no boot menu on but direct boot into rockbox if hold button is not on hold)
Altering the bootloader to my needs is not the problem, nor compiling it. But i have troube to create an upg file for the update

1. compiling of and executing of rockbox work  =>OK

2. compiling of bootloader works  => OK

3. compiling mknwzboot fails !  =>


4. compiling upgtools works = >OK

mknwzboot has a dependency to  utils/nwztools/upgtool
but this seems to be broken :
The Makefile has references to md5.c  and mg.c which do not exist.
Because mg.cpp does exist i think that upgtools were updated but not the mknwzboot's makefile

Update :

i edited Makefile of mknwzboot  to build it sucessfully  :
UPGTOOLS_SOURCES = misc.c upg.c fwp.c mg.cpp md5.cpp
UPGTOOLS_SOURCES = misc.c upg.c  mg.cpp keysig_search.c <= this seems to be fine



Unfortuantely i always get a segfault when using:
../rbutil/mknwzboot/mknwzboot -o NW_WM_FW.UPG -b bootloader-nwze580.sony
[INFO] Bootloader file for Sony NWZ-E580 Series
Segmentation fault (core dumped)

The same goes for  upgtool which i can build unmodified

./upgtool -m nwz-e580 -c bootloader-nwze580.sony
Keys
  KAS: 6e25f79812eca7ceed04819d833e80af
  Key: a70807da
  Sig: 97e8ce46
Segmentation fault (core dumped)

so probably something is wrong with my build system , i don't know ?
(im usung linux mint 20 within virtualbox )

Has anyone a working build of mknwzboot and upgtool for win32 for me to play with ?

thanks in advance Max