Failed to emerge app-i18n/ibus-1.4.1

log:

  GISCAN IBus-1.0.gir
Package ibus-1.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `ibus-1.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'ibus-1.0' found
In file included from /var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1/src/ibus.h:28:0,
                 from <stdin>:4:
./ibusshare.h:39:18: fatal error: glib.h: No such file or directory
compilation terminated.
Error while processing the source.
make[4]: *** [IBus-1.0.gir] Error 1
make[4]: Leaving directory `/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1/src'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1/src'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1/src'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1'
make: *** [all] Error 2
 * ERROR: app-i18n/ibus-1.4.1 failed (compile phase):
 *   emake failed
 * 
 * If you need support, post the output of 'emerge --info =app-i18n/ibus-1.4.1',
 * the complete build log and the output of 'emerge -pqv =app-i18n/ibus-1.4.1'.
 * The complete build log is located at '/var/tmp/portage/app-i18n/ibus-1.4.1/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/app-i18n/ibus-1.4.1/temp/environment'.
 * S: '/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1'

>>> Failed to emerge app-i18n/ibus-1.4.1, Log file:

>>>  '/var/tmp/portage/app-i18n/ibus-1.4.1/temp/build.log'

 * Messages for package app-i18n/ibus-1.4.1:

 * ERROR: app-i18n/ibus-1.4.1 failed (compile phase):
 *   emake failed
 * 
 * If you need support, post the output of 'emerge --info =app-i18n/ibus-1.4.1',
 * the complete build log and the output of 'emerge -pqv =app-i18n/ibus-1.4.1'.
 * The complete build log is located at '/var/tmp/portage/app-i18n/ibus-1.4.1/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/app-i18n/ibus-1.4.1/temp/environment'.
 * S: '/var/tmp/portage/app-i18n/ibus-1.4.1/work/ibus-1.4.1'

 * IMPORTANT: 5 news items need reading for repository 'gentoo'.
 * Use eselect news to read news items.

How could I fix it ?

USE “-introspection” to ibus will fix it.