Looking at the circuit diagrams the busblaster V4

There are changes to the port and also some output enable buffers

This appears to change the way the unit works.

The busblaster v4 works fine with openocd but fails for ftjrev

./ftjrev scan
Chain sizing failed

make
gcc -Wall -O2 -o ftjrev ftjrev.c -lftdi
ftjrev.c:10:10: fatal error: 'ftdi.h' file not found

include <ftdi.h>

     ^

1 error generated.
make: *** [ftjrev] Error 1

either there needs to be instructions on where to find library and how to include it
or it should be included………