Installing ToolChain for wp750x_red release 16.1 SWI9X15Y_07.13.05.00


I am following the Getting Started Guide to install the newest toolChain for my wp750x_red
Step j. says:
When prompted for the installation directory, append the version number from Step g to the default directory name:

For example, “/opt/swi/y22-ext-SWI9X07Y_02.14.04.00”.

But when installing SWI9X15Y_07.13.05.00 it claims that the default directory name is:
Enter target directory for SDK (default: /opt/swi/SWI9X15Y_07.13.05.00):
The default directory already includes the version number and it is without y22-ext-)

Should I need to add that y22-ext prefix or it is not important?

And do I need to follow step I. when I have Release 16.1 ?
(l.If the module is a WP7502, WP7504, or WP8548 that has Release 15 firmware, additional scripts must be built:…

The problem is that when I want to Build the Legato AF and mangOH platforms for the CF3 module with
make clean && make red_wp750x
it will fail with

legato_framework/legato/framework/include/legato.h:146:20: fatal error: unistd.h: No such file or directory
 #include <unistd.h>