Failed to emerge dev-java/ant-core-1.7.1-r4

Problème

When i update my gentoo, i've the following problem :
Failed to emerge dev-java/ant-core-1.7.1-r4

It's java_config fault :
Traceback (most recent call last):
File "/usr/bin/java-config-2", line 8, in
from java_config_2 import __version__
ImportError: No module named java_config_2

Solution

You have to emerge java_config once again :
=> Solution : emerge -l java-config



Example of failed compilation :
Traceback (most recent call last):
File "/usr/bin/java-config-2", line 8, in
from java_config_2 import __version__
ImportError: No module named java_config_2
*
* Can't run java-config --help
* Have you upgraded python recently but haven't
* run python-updater yet?
*
* ERROR: dev-java/ant-core-1.7.1-r4 failed.
* Call stack:
* ebuild.sh, line 49: Called pkg_setup
* ebuild.sh, line 1273: Called java-pkg-2_pkg_setup
* java-pkg-2.eclass, line 61: Called java-pkg_init
* java-utils-2.eclass, line 2050: Called die
* The specific snippet of code:
* die "Can't run java-config --help"
* The die message:
* Can't run java-config --help
*
* If you need support, post the topmost build error, and the call stack if relevant.
* A complete build log is located at '/var/tmp/portage/dev-java/ant-core-1.7.1-r4/temp/build.log'.
* The ebuild environment file is located at '/var/tmp/portage/dev-java/ant-core-1.7.1-r4/temp/die.env'.
*
!!! When you file a bug report, please include the following information:
GENTOO_VM= CLASSPATH="." JAVA_HOME=""
JAVACFLAGS="" COMPILER=""
and of course, the output of emerge --info

>>> Failed to emerge dev-java/ant-core-1.7.1-r4, Log file:

>>> '/var/tmp/portage/dev-java/ant-core-1.7.1-r4/temp/build.log'

* Messages for package dev-java/ant-core-1.7.1-r4:

*
* Can't run java-config --help
* Have you upgraded python recently but haven't
* run python-updater yet?
*
* ERROR: dev-java/ant-core-1.7.1-r4 failed.
* Call stack:
* ebuild.sh, line 49: Called pkg_setup
* ebuild.sh, line 1273: Called java-pkg-2_pkg_setup
* java-pkg-2.eclass, line 61: Called java-pkg_init
* java-utils-2.eclass, line 2050: Called die
* The specific snippet of code:
* die "Can't run java-config --help"
* The die message:
* Can't run java-config --help
*
* If you need support, post the topmost build error, and the call stack if relevant.
* A complete build log is located at '/var/tmp/portage/dev-java/ant-core-1.7.1-r4/temp/build.log'.
* The ebuild environment file is located at '/var/tmp/portage/dev-java/ant-core-1.7.1-r4/temp/die.env'.