[gentoo-portage-dev] PATCH: initial EAPI awareness

[Brian Harring]

Hola.

Attached is a patch that 
A) adds EAPI awareness to portage; mainly, if >0, complain and be 
   unwilling to merge the package
B) tweaks to portage_db_flat, addition of portage_db_metadata, and 
   portage_db_flat_hash

Flat_hash is the replacement cache format for metadata/cache; assuming 
nobody does anything stupid with EAPI, it will allow us to deploy new 
metadata in the tree without forcing a breakage every time we do so.

portage_db_metadata.py is a compability implementation; basically 
detects if it's flat_list (portage_db_flat), or flat_hash and calls 
accordingly.

Aside from that, tried to keep changes as minimal as possible.  The 
patch isn't complete due to the fact we need to add an EAPI cache 
compatibility check for --metadata transfer, but can't do that till I 
get some feedback from -dev ml regarding a bit of tree cleanup that 
will go along with it.

Please test this out; if you want to test the EAPI checking, tag 
EAPI=1 into an ebuild, and try making emerge bail.

If you're less adventurous, please test the compatibility cache 
testing; 
in /etc/portage/modules
portdbapi.metadbmodule=portage_db_metadata.database

Will enable the autodetection.  Additionally, 
portdbapi.auxdbmodule=portage_db_flat_hash.database

being flipped on would be appreciated, although you will have to wipe 
your cache and run emerge --metadata; with the settings above, you're 
testing the auto-detect functionality, and the new format.

Thanks,
~harring