On mediawiki 1.16alpha-svn, which could be successfully updated to svn -r52502 (after running update.php successfully all seemed to work), updating further to newest revision 55744 of today, running upgrade.php produces the following error message:
A database error has occurred
Query: SELECT lc_value FROM l10n_cache WHERE lc_lang = 'en' AND lc_key = 'deps' LIMIT 1
Error: 1146 Table 'testwiki.l10n_cache' doesn't exist
The mediawiki installation then no longer works since update is unable to run.
Note that the mediawiki in question was setup for English-language (bug19447, also related to I10n_cache that is supposed to be fixed was limited to non-english wiki setups).