更新：why-not按照建议 添加了输出（why也添加了输出）。
# aptitude why-not libwbclient0
Unable to find a reason to remove libwbclient0.` `why` gives this reasoning.
# aptitude why libwbclient0
i nagios-plugins-standard Recommends smbclient
p smbclient Depends samba-libs (= 2:4.3.11+dfsg-0ubuntu0.14.04.11)
p samba-libs Depends libwbclient0 (>= 2:4.0.3+dfsg1)
为什么aptitude upgrade这里无法真正升级软件包，而apt-get upgrade愿意执行？据我所知，这两个命令在功能上应该相同，但显然它们不一致。有人能解释如何在这里找到问题，以及为什么它对一个命令有效，而对另一个命令无效吗？
资质
# aptitude upgrade
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.
apt-get
# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
libwbclient0
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 30.0 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n]