system:
Gentoo Base System release 2.0.3
x86_64

gentoo-zh git:
commit e740c1c3e32af4a15444549ae971e4f60d9c4153
Author: microcai <microcai@fedoraproject.org>
Date:   Tue Jan 10 09:31:45 2012 +0800

error info:
x86_64-pc-linux-gnu-g++ -c -pipe -I./libfetion/include -I./src -I./.ui -O2 -pipe -march=core2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_XMLPATTERNS_LIB -DQT_XML_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtXml -I/usr/include/qt4/QtXmlPatterns -I/usr/include/qt4 -I. -I.moc -I.ui -o .tmp/fxqunwindow.o src/fxqunwindow.cpp
src/fxcontactinfo.cpp: In member function ‘QString FxContactInfo::getContactInfo()’:
src/fxcontactinfo.cpp:203:3: error: call of overloaded ‘QString(NULL)’ is ambiguous
/usr/include/qt4/QtCore/qstring.h:428:43: note: candidates are: QString::QString(const QByteArray&)
/usr/include/qt4/QtCore/qstring.h:426:43: note:                 QString::QString(const char*)
/usr/include/qt4/QtCore/qstring.h:728:8: note:                 QString::QString(const QString&)
/usr/include/qt4/QtCore/qstring.h:106:5: note:                 QString::QString(QChar)
/usr/include/qt4/QtCore/qstring.h:105:14: note:                 QString::QString(const QChar*)
src/fxcontactinfo.cpp:206:3: error: call of overloaded ‘QString(NULL)’ is ambiguous
/usr/include/qt4/QtCore/qstring.h:428:43: note: candidates are: QString::QString(const QByteArray&)
/usr/include/qt4/QtCore/qstring.h:426:43: note:                 QString::QString(const char*)
/usr/include/qt4/QtCore/qstring.h:728:8: note:                 QString::QString(const QString&)
/usr/include/qt4/QtCore/qstring.h:106:5: note:                 QString::QString(QChar)
/usr/include/qt4/QtCore/qstring.h:105:14: note:                 QString::QString(const QChar*)
src/fxcontactinfo.cpp:212:3: error: call of overloaded ‘QString(NULL)’ is ambiguous
/usr/include/qt4/QtCore/qstring.h:428:43: note: candidates are: QString::QString(const QByteArray&)
/usr/include/qt4/QtCore/qstring.h:426:43: note:                 QString::QString(const char*)
/usr/include/qt4/QtCore/qstring.h:728:8: note:                 QString::QString(const QString&)
/usr/include/qt4/QtCore/qstring.h:106:5: note:                 QString::QString(QChar)
/usr/include/qt4/QtCore/qstring.h:105:14: note:                 QString::QString(const QChar*)
make: *** [.tmp/fxcontactinfo.o] Error 1
make: *** Waiting for unfinished jobs....
emake failed
 * ERROR: net-im/linux-fetion-1.2 failed (compile phase):
 *   emake failed
 * 
 * Call stack:
 *            ebuild.sh, line   75:  Called src_compile
 *          environment, line 2839:  Called default
 *   phase-functions.sh, line  791:  Called _eapi2_src_compile
 *     phase-helpers.sh, line  577:  Called die
 * The specific snippet of code:
 *   		emake || die "emake failed"
 * 
 * If you need support, post the output of 'emerge --info =net-im/linux-fetion-1.2',
 * the complete build log and the output of 'emerge -pqv =net-im/linux-fetion-1.2'.
 * The complete build log is located at '/var/tmp/portage/net-im/linux-fetion-1.2/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/net-im/linux-fetion-1.2/temp/environment'.
 * S: '/var/tmp/portage/net-im/linux-fetion-1.2/work/linux_fetion_v1.2'

>>> Failed to emerge net-im/linux-fetion-1.2, Log file:

>>>  '/var/tmp/portage/net-im/linux-fetion-1.2/temp/build.log'

 * Messages for package net-im/linux-fetion-1.2:

 * ERROR: net-im/linux-fetion-1.2 failed (compile phase):
 *   emake failed
 * 
 * Call stack:
 *            ebuild.sh, line   75:  Called src_compile
 *          environment, line 2839:  Called default
 *   phase-functions.sh, line  791:  Called _eapi2_src_compile
 *     phase-helpers.sh, line  577:  Called die
 * The specific snippet of code:
 *   		emake || die "emake failed"
 * 
 * If you need support, post the output of 'emerge --info =net-im/linux-fetion-1.2',
 * the complete build log and the output of 'emerge -pqv =net-im/linux-fetion-1.2'.
 * The complete build log is located at '/var/tmp/portage/net-im/linux-fetion-1.2/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/net-im/linux-fetion-1.2/temp/environment'.
 * S: '/var/tmp/portage/net-im/linux-fetion-1.2/work/linux_fetion_v1.2'