This is on Gentoo Linux (~x86 aka not the stable version).
A few days ago, the new version of GNU patch (patch-2.6) became available.
Since then the building of openoffice fails, rather: it does not even start
- because patch-2.6 is not recognized by the build scripts as a valid version to
do the job.

Downgrading patch to the previous version (patch-2.5.9-r1) will work as expected:
I now have openoffice OOO310m19 (build:9420) - at the bottom it says: "Build
3.1.1.4" running.


The failure message, when patch-2.6 is used, is:
...
Execute with  for distro(s) 'Gentoo Binfilter System Sdk Extensions Localize'
Can't get patch version
make: *** [stamp/patch.apply] Error 255
..."

The reason seems to be in line 923 of

ooo-build-3.1.1.4/patches/apply.pl.in

which seems to do the parsing
The following line checks for a version greater or equal to 2.5.9 but the script
does not get there with patch-2.6 installed.

output of "patch --version" is for me:

patch --version
patch 2.6
Copyright (C) 1988 Larry Wall
Copyright (C) 2003 Free Software Foundation, Inc.

This program comes with NO WARRANTY, to the extent permitted by law.
You may redistribute copies of this program
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING.

written by Larry Wall and Paul Eggert


and this is the parsing code which fails on patch 2.6

$ver_line =~ m/\s+(\d+)\.(\d+)\.(\d+)/ || die "Can't get patch version\n";

If I where able to decipher this I would have suggested a fix...

There is a bug-report on bugs.gentoo.org - #293385
http://bugs.gentoo.org/show_bug.cgi?id=293385
but I suppose this place is better suited.

I hope this (OOO310m19) is the right category - it is an issue with all
versions, I suppose.