Is Xvid really missing a CLI parameter for xvid_encraw (like '-V' or '--version') which prints the version number and quits? I could only find one way to make xvid_encraw print it: When it passes the parameter sanity check and actually tries to encode something. There is no version number contained in the help output. So the fastest way to query the version seems to be:
Just for fun - nothing important happened, only a fresh compile in MABS.
Xvid CLI 1.3.5 (MSYS2, MinGW32 / MinGW64 + GCC 9.1.0)