windows 10 vc 2017 getting this error : ninja: error: loading 'build.ninja': The system cannot find the file specified.

[umen]

hello all

i try to compile v8 debug as static lib 

this are the steps i did according from those links on the www:

http://blogs.stonesteps.ca/showpost.aspx?pid=65

https://medium.com/dailyjs/how-to-build-v8-on-windows-and-not-go-mad-6347c69aacd4

but im getting error when i build with the "ninja: 

D:\Dev\my\v8\v8>ninja -v -C  out.gn\x64.debug
ninja: error: loading 'build.ninja': The system cannot find the file specified.


ninja: Entering directory `out.gn\x64.debug'

out.gn\x64.debug\args.gn looks like this :

is_debug = true
target_cpu = "x64"
v8_enable_backtrace = true
v8_enable_slow_dchecks = true
v8_optimized_debug = false
v8_use_snapshot=true
v8_use_external_startup_data=false
is_component_build = false
v8_static_library = true

in my out.gn\x64.debug i have all the dll files files that have been created 

api-ms-win-core-console-l1-1-0.dll
api-ms-win-core-datetime-l1-1-0.dll
api-ms-win-core-debug-l1-1-0.dll
api-ms-win-core-errorhandling-l1-1-0.dll
api-ms-win-core-file-l1-1-0.dll
api-ms-win-core-file-l1-2-0.dll
api-ms-win-core-file-l2-1-0.dll
api-ms-win-core-handle-l1-1-0.dll
api-ms-win-core-heap-l1-1-0.dll
api-ms-win-core-interlocked-l1-1-0.dll
api-ms-win-core-libraryloader-l1-1-0.dll
api-ms-win-core-localization-l1-2-0.dll
api-ms-win-core-memory-l1-1-0.dll
api-ms-win-core-namedpipe-l1-1-0.dll
api-ms-win-core-processenvironment-l1-1-0.dll
api-ms-win-core-processthreads-l1-1-0.dll
api-ms-win-core-processthreads-l1-1-1.dll
api-ms-win-core-profile-l1-1-0.dll
api-ms-win-core-rtlsupport-l1-1-0.dll
api-ms-win-core-string-l1-1-0.dll
api-ms-win-core-synch-l1-1-0.dll
api-ms-win-core-synch-l1-2-0.dll
api-ms-win-core-sysinfo-l1-1-0.dll
api-ms-win-core-timezone-l1-1-0.dll
api-ms-win-core-util-l1-1-0.dll
api-ms-win-crt-conio-l1-1-0.dll
api-ms-win-crt-convert-l1-1-0.dll
api-ms-win-crt-environment-l1-1-0.dll
api-ms-win-crt-filesystem-l1-1-0.dll
api-ms-win-crt-heap-l1-1-0.dll
api-ms-win-crt-locale-l1-1-0.dll
api-ms-win-crt-math-l1-1-0.dll
api-ms-win-crt-multibyte-l1-1-0.dll
api-ms-win-crt-private-l1-1-0.dll
api-ms-win-crt-process-l1-1-0.dll
api-ms-win-crt-runtime-l1-1-0.dll
api-ms-win-crt-stdio-l1-1-0.dll
api-ms-win-crt-string-l1-1-0.dll
api-ms-win-crt-time-l1-1-0.dll
api-ms-win-crt-utility-l1-1-0.dll
args.gn
dbgcore.dll
dbghelp.dll
environment.x64
msvcp140.dll
msvcp140d.dll
ucrtbase.dll
ucrtbased.dll
vccorlib140.dll
vccorlib140d.dll
vcruntime140.dll
vcruntime140d.dll

why is this error ? and how can i fix it ?

thanks 

[umen]

Answering to my self and to whom is looking for answer 
the command to generate the ninja files is (dont miss the "args"  :

gn args out.gn\x64.debug