Build fails for edgecore platform

[w1kl4s]

After building all packages according to instructions from here, i tried building for edgecore platform with

opx-build/scripts/opx_run opx_rel_pkgasm.py --dist stable \
  -b opx-onie-installer/release_bp/OPX_edgecore_base_stretch.xml

But it eventually fails with

Traceback (most recent call last):                                                                                                                                                                                                      
  File "/opt/opx-build/scripts/opx_rel_pkgasm.py", line 1403, in <module>                                                                                                                                                               
    sys.exit(main())                                                                                                                                                                                                                    
  File "/opt/opx-build/scripts/opx_rel_pkgasm.py", line 1353, in main                                                                                                                                                                   
    rel_plan.add_packages()                                                                                                                                                                                                             
  File "/opt/opx-build/scripts/opx_rel_pkgasm.py", line 946, in add_packages                                                                                                                                                            
    packer.fetch(names=deb_package_list)                                                                                                                                                                                                
  File "/opt/opx-build/scripts/opx_get_packages.py", line 446, in fetch                                                                                                                                                                 
    pkg = self._cache[package_name]                                                                                                                                                                                                     
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 200, in __getitem__
    raise KeyError('The cache has no package named %r' % key)
opx_get_packages.OpxPackagesError: Can't find opx-edgecore-as7512-32x in package cache

How can i build this package?