ImportError: No module named java_config_2

Das letzte Systemupdate mittels emerge -uND world lief problemlos durch. Bis das Paket dev-java/antlr-2.7.7 an die Reihe kam. Hier brach die Installation mit folgender Fehlermeldung ab: 

# emerge -uND world
Calculating world dependencies... done!
>>> Verifying ebuild Manifests...

>>> Emerging (1 of 148) dev-java/antlr-2.7.7 to /
 * antlr-2.7.7.tar.gz RMD160 SHA1 SHA256 size ;-) ...                                                                                                                        [ ok ]
 * checking ebuild checksums ;-) ...                                                                                                                                         [ ok ]
 * checking auxfile checksums ;-) ...                                                                                                                                        [ ok ]
 * checking miscfile checksums ;-) ...                                                                                                                                       [ ok ]
 * checking antlr-2.7.7.tar.gz ;-) ...                                                                                                                                       [ ok ]
Traceback (most recent call last):
  File "/usr/bin/depend-java-query", line 8, in <module>
    from java_config_2 import __version__
ImportError: No module named java_config_2
 * Unable to determine VM for building from dependencies:
NV_DEPEND: >=virtual/jdk-1.3
        mono? ( dev-lang/mono )
        python? ( dev-lang/python )
        script? ( !dev-util/pccts )
        source? ( app-arch/zip )  >=dev-java/java-config-2.0.33-r1 >=sys-apps/portage-2.1.2.7 virtual/python
VNEED: 
 * 
 * ERROR: dev-java/antlr-2.7.7 failed.
 * Call stack:
 *               ebuild.sh, line   49:  Called pkg_setup
 *               ebuild.sh, line 1244:  Called java-pkg-2_pkg_setup
 *       java-pkg-2.eclass, line   60:  Called java-pkg_init
 *     java-utils-2.eclass, line 2090:  Called java-pkg_switch-vm
 *     java-utils-2.eclass, line 2516:  Called die
 * The specific snippet of code:
 *                              die "Failed to determine VM for building."
 *  The die message:
 *   Failed to determine VM for building.
 * 
 * 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/antlr-2.7.7/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/dev-java/antlr-2.7.7/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

 * Messages for package dev-java/antlr-2.7.7:

 * Unable to determine VM for building from dependencies:
 * 
 * ERROR: dev-java/antlr-2.7.7 failed.
 * Call stack:
 *               ebuild.sh, line   49:  Called pkg_setup
 *               ebuild.sh, line 1244:  Called java-pkg-2_pkg_setup
 *       java-pkg-2.eclass, line   60:  Called java-pkg_init
 *     java-utils-2.eclass, line 2090:  Called java-pkg_switch-vm
 *     java-utils-2.eclass, line 2516:  Called die
 * The specific snippet of code:
 *                              die "Failed to determine VM for building."
 *  The die message:
 *   Failed to determine VM for building.
 * 
 * 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/antlr-2.7.7/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/dev-java/antlr-2.7.7/temp/die.env'.

Auf dem ersten Blick ist nich erkennbar, wo genau die Ursache für dieses Problem ist. Doch bei genauerem Hinschauen ist zu erkennen, dass es ein Abhängigkeitsproblem gibt.

Lösung

Folgender Teil der oben gezeigten Ausgabe zeigt die Ursache des Problems: 

Traceback (most recent call last):
  File "/usr/bin/depend-java-query", line 8, in <module>
    from java_config_2 import __version__
ImportError: No module named java_config_2
 * Unable to determine VM for building from dependencies:
  File "/usr/bin/depend-java-query", line 8, in <module>
    from java_config_2 import __version__
ImportError: No module named java_config_2
 * Unable to determine VM for building from dependencies:
NV_DEPEND: >=virtual/jdk-1.3
        mono? ( dev-lang/mono )
        python? ( dev-lang/python )
        script? ( !dev-util/pccts )
        source? ( app-arch/zip )  >=dev-java/java-config-2.0.33-r1 >=sys-apps/portage-2.1.2.7 virtual/python
VNEED:

Hier existiert ein Problem mit dem Paket java-config, welches nicht korrekt installiert zu sein scheint. Dieses bestätigt sich, wenn man java-config startet. Hier treten Folgefehler auf.

Nach der Neuinstallation von java-config konnte das Problem behoben werden: 

# emerge -av java-config

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R   ] dev-java/java-config-2.1.6  0 kB 

Total: 1 package (1 reinstall), Size of downloads: 0 kB

Would you like to merge these packages? [Yes/No]

Ratsam ist es auch, die anderen Pakete (mono, python, pccts und zip) zu überprüfen, wenn der Fehler weiterhin auftritt.