ninja: error: unknown target 'multirom', did you mean 'multihal'?

[LgPWNd]

Hi I've been trying to build multirom for my device the Alcatel tetra 5041C.
Problem is I'm using the old instructions on github....
and for what ever reason, I add libbootimg to system/extras/
and i add multirom to system/extras/
and do submodule git init.
just like instructions in read me but get the following error...

ninja: error: unknown target 'multirom', did you mean 'multihal'?

can some one please tell me where I'm missing something here?

I'm using omnirom sources i repo synced the whole android source for 9.0
I also tried to insert this into the build system of my custom recovery and got the same error

any help appriciated .
feel free to drop by our telegram group...
https://t.me/Alcatel_devices_LgPWNd

[xing2387]

You need do some configuration in devices/xx/xx/BoardConfig.mk

see:
https://github.com/Tasssadar/android_device_lge_hammerhead/blob/093093e211b2bb42b7d27b8180cbcd3c2cdbf64e/BoardConfig.mk

-----update
Read this guide:
https://github.com/Tasssadar/multirom/wiki/Porting-MultiROM

I'm a newbie ...