Already tried many ways: pkgbuild, productbuild, PackageMaker, Packages application...
The structure of the flat package that I want to build:
Distribution - xml script
MacBookPro2011EFIUpdate.pkg - flat package
Resources - resources folder, contains language localizations
Flat package information:
id="com.apple.pkg.MacBookPro2011EFIUpdate" version="2.7.0.0.1.1330468277"
For example, my failure with productbuild:
productbuild: error: Cannot copy package "MacBookPro2011EFIUpdate.pkg" into product.
(Bundle-style package "MacBookPro2011EFIUpdate.pkg" is not supported.)
Please, try to build the installer package from these files: Link
And, if you succeed, please tell how you did that!