FLASHC

Calculating dependencies... done!
[ebuild  N    ] gnome-base/gdm-2.20.10-r2  USE="consolekit ipv6 pam tcpd -accessibility -afs -branding -debug -dmx -gnome-keyring -remote (-selinux) -xinerama" 0 kB

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

!!! The following installed packages are masked:
- app-emulation/virtualbox-bin-3.0.8 (masked by: PUEL license(s))
A copy of the 'PUEL' license is located at '/usr/portage/licenses/PUEL'.

- dev-java/sun-jdk-1.6.0.16 (masked by: dlj-1.1 license(s))
A copy of the 'dlj-1.1' license is located at '/usr/portage/licenses/dlj-1.1'.

For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.


 * IMPORTANT: 3 news items need reading for repository 'gentoo'.
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Sol:
一是在/etc/make.conf里面加入下面一行：

ACCEPT_LICENSE="PUEL"

二是在etc/portage/package.license里面添加下面的一行就可以了：

app-emulation/virtualbox-bin PUEL