I've reproduced it:
$ cd xwiki-product-enterprise/database/
$ mvn clean install
produce empty hsql db.
while
$ cd xwiki-product-enterprise/database/hsql
$ mvn clean install
works fine.
looks like 
http://markmail.org/message/cmqtvc2neuux5spn
It skip these goals:
[INFO] [xwiki-xar:unxar]
[INFO] [xwiki-packager-plugin:import]
So I change my vote to -1.
Sergiu Dumitriu wrote:
  -1
 I tried it first to see if it works. On a clean trunks, the first build
 was wrong, meaning that the final distribution zip didn't have any skins
 and the database directory wasn't found, although it was there. Tried
 again with the 2.1 snapshot a clean + install, and it worked fine. Tried
 again with 2.0.9 a clean + install and it worked fine. Then I cleaned
 the local repo (only the xwiki packages) and built again, using 2.0.9,
 and I got a broken build.
 Can somebody else reproduce this? 
--
  Artem Melentyev