当我gedit在终端中输入时，我得到：
daniel@daniel-pc:~$ gedit
The program 'gedit' is currently not installed. You can install it by typing:
sudo apt-get install gedit
所以我这样做：
daniel@daniel-pc:~$ sudo apt-get install gedit
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
gedit : Depends: gedit-common (< 3.11) but 3.12.2-0ubuntu1~trusty1 is to be installed
E: Unable to correct problems, you have held broken packages.
daniel@daniel-pc:~$
背景：
我遵循了在http://howtoubuntu.org/things-to-do-after-installing-ubuntu-14-10-utopic-unicorn，但在我注意到许多基本程序（如 getedit 和 nautilus）具有 gnome 风格而不是 unity 风格后，我从 GUI 软件和更新中删除了 PPA。
我也sudo apt-get install edubuntu-desktop尝试获取在 edubuntu 中找到的程序，但是在它更改主题和背景后，我按照此处的说明进行操作：如何删除包中的所有程序？，从返回的列表中选择我不想要的程序。我运行
daniel@daniel-pc:~$ apt-cache show gedit
Package: gedit
Priority: optional
Section: gnome
Installed-Size: 2615
Maintainer: Ubuntu Desktop Team <[email protected]>
Original-Maintainer: Debian GNOME Maintainers [email protected]
Architecture: amd64
Version: 3.10.4-0ubuntu6
Depends: libatk1.0-0 (>= 1.12.4), libc6 (>= 2.14), libcairo2 (>= 1.2.4), libenchant1c2a (>= 1.6.0), libgdk-pixbuf2.0-0 (>= 2.22.0), libgirepository-1.0-1 (>= 0.9.3), libglib2.0-0 (>= 2.38), libgtk-3-0 (>= 3.10), libgtksourceview-3.0-1 (>= 3.10.1), libpango-1.0-0 (>= 1.14.0), libpeas-1.0-0 (>= 1.1.0), libx11-6, libxml2 (>= 2.7.4), libzeitgeist-2.0-0 (>= 0.9.9), gedit-common (>= 3.10), gedit-common (<< 3.11), gsettings-desktop-schemas, python3-gi (>= 3.0), python-gi-cairo (>= 3.0), gir1.2-peas-1.0, iso-codes
Recommends: gir1.2-gtksource-3.0, zenity, yelp
Suggests: gedit-plugins
Breaks: gedit-plugins (<< 2.91)
Filename: pool/main/g/gedit/gedit_3.10.4-0ubuntu6_amd64.deb
Size: 483208
MD5sum: 3e4508090c23d68053212ab02cb0287c
SHA1: 9f38aafddfa21cd2743b863b1783710a5360d0d2
SHA256: d43073382e1b9894abecfcd8fe6a04e2c771f6aabe0891e666a8f59ee2107283
Description-en: official text editor of the GNOME desktop environment
gedit is a text editor which supports most standard editor features,
extending this basic functionality with other features not usually
found in simple text editors. gedit is a graphical application which
supports editing multiple text files in one window (known sometimes as
tabs or MDI).
.
gedit fully supports international text through its use of the Unicode
UTF-8 encoding in edited files. Its core feature set includes syntax
highlighting of source code, auto indentation and printing and print preview
support.
.
gedit is also extensible through its plugin system, which currently
includes support for spell checking, comparing files, viewing CVS
ChangeLogs, and adjusting indentation levels.
Description-md5: 5091aaf6659e6bf7ca9b32695a59f9cd
Homepage: http://www.gnome.org/projects/gedit/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
Supported: 9m
Task: ubuntu-desktop, ubuntu-usb, edubuntu-desktop, edubuntu-usb, ubuntustudio-desktop, ubuntu-gnome-desktop, ubuntukylin-desktop
daniel@daniel-pc:~$
所以它说 gedit 已安装，但实际上没有。我尝试通过执行“sudo apt-get remove gedit=”和版本号来卸载 Gnome 版本的 gedit，但我不记得了。
编辑：
daniel@daniel-pc:~$ apt-cache policy gedit-common
gedit-common:
Installed: 3.12.2-0ubuntu1~trusty1
Candidate: 3.12.2-0ubuntu1~trusty1
Version table:
*** 3.12.2-0ubuntu1~trusty1 0
100 /var/lib/dpkg/status
3.10.4-0ubuntu6 0
500 http://us.archive.ubuntu.com/ubuntu/ utopic/main amd64 Packages
daniel@daniel-pc:~$
编辑：现在的 nautulus 图像，这是 gedit 在卸载之前的样子：关联看看菜单栏。它看起来像 gnome，而不是默认的 unity。此外，我希望有一个适用于所有受此影响的程序的通用解决方案，而不仅仅是 gedit 和 nautilus（尽管我不知道是否有任何程序）。
答案1
第一次运行
sudo apt-get purge gedit gedit-common
sudo apt-get clean
然后安装 gedit 后使用
sudo apt-get install gedit
它应该可以工作。
答案2
对我有用的是，
sudo apt-get update
然后尝试再次安装
apt install gedit