Building unofficial LineageOS port with lunch

I'm working on an unofficial LOS 14.1 port for the Samsung Galaxy Ace 4 Neo SM-G316ML. I currently have the LOS and kernel sources in GitLab, not GitHub.

I've created the local_manifest.xml file with the following:

<?xml version="1.0" encoding="UTF-8"?>
<manifest>

  <remote  name="gitlab" 
           fetch="https://gitlab.com/"
           revision="cm-14.1" />

  <project name="Megver83/android_device_samsung_vivalto3mve3gltn" path="device/samsung/vivalto3mve3gltn" remote="gitlab" />
  <project name="Megver83/android_kernel_samsung_vivalto3mve3gltn" path="kernel/samsung/vivalto3mve3gltn" remote="gitlab" />

</manifest>

Which works pretty good (repo sync syncs well). Then (after doing . build/envsetup.sh of course) I added the luch combo:

$ add_lunch_combo lineage_vivalto3mve3gltn-userdebug

But here comes the ugly part:

$ lunch lineage_vivalto3mve3gltn-userdebug
build/core/config.mk:676: COMMON_GLOBAL_C(PP)FLAGS changed
build/core/config.mk:680: *** bailing....  Stop.
Device vivalto3mve3gltn not found. Attempting to retrieve device repository from LineageOS Github (http://github.com/LineageOS).
Repository for vivalto3mve3gltn not found in the LineageOS Github repository list. If this is in error, you may need to manually add it to your local_manifests/roomservice.xml.
build/core/config.mk:676: COMMON_GLOBAL_C(PP)FLAGS changed
build/core/config.mk:680: *** bailing....  Stop.
build/core/config.mk:676: COMMON_GLOBAL_C(PP)FLAGS changed
build/core/config.mk:680: *** bailing....  Stop.

** Don't have a product spec for: 'lineage_vivalto3mve3gltn'
** Do you have the right repo manifest?

Which I don't understand, since according to what I read here, this function is used for compiling unofficial builds, but the error message says that the device was not found LineageOS's Github.

So, what's the correct way for compiling an unofficial LOS build?
Thanks in advance

Solution

Finally, I got the answer in this XDA thread

go to build/core and gedit config.mk. Then add # to each line like shown below

only to these lines:

# ################################################## #############
# Set up final options.
# ################################################## #############

#ifneq ($(COMMON_GLOBAL_CFLAGS)$(COMMON_GLOBAL_CPPFLAGS), )
#$(warning COMMON_GLOBAL_C(PP)FLAGS changed)
#$(info *** Device configurations are no longer allowed to change the global flags.)
#$(info *** COMMON_GLOBAL_CFLAGS: $(COMMON_GLOBAL_CFLAGS))
#$(info *** COMMON_GLOBAL_CPPFLAGS: $(COMMON_GLOBAL_CPPFLAGS))
#$(error bailing...)
#endif

And problem solved. Now I can lunch/breakfast without problem.