我必须处理 Debian 服务器，我相信它最初是 Squeeze，但管理员启用了多个发行版：
deb http://mirror.yandex.ru/debian/ stable main contrib non-free
deb http://mirror.yandex.ru/debian/ testing main contrib non-free
deb http://security.debian.org/ testing/updates main contrib non-free
deb http://mirror.yandex.ru/debian/ unstable main contrib non-free
deb http://mirror.yandex.ru/debian/ experimental main contrib non-free
并在/etc/apt/apt.conf:中指定APT::Default-Release "testing";。
因此，当我询问 aptitude 或 apt 关于某个软件包的状态时，它会带来有争议的证词：
me@server: aptitude search emboss
i A emboss - european molecular biology open software suite
me@server: aptitude show emboss
Package: emboss
New: yes
State: not installed
Automatically installed: yes
...
apt-cache show emboss显示有关感兴趣的包（“emboss”）的 4 个副本的信息，其中一个副本包含 line Status: install ok installed，我认为这意味着它已安装。
Package: emboss
Status: install ok installed
Priority: optional
Section: science
Installed-Size: 4020
Maintainer: Debian Med Packaging Team <[email protected]>
Architecture: amd64
Version: 6.3.1-6
Depends: emboss-lib (= 6.3.1-6), libc6 (>= 2.7), libexpat1 (>= 1.95.8), libfontconfig1 (>= 2.8.0), libfreetype6 (>= 2.2.1), libgd2-noxpm (>= 2.0.36~rc1~dfsg) | libgd2-xpm (>= 2.0.36~rc1~dfsg), libhpdf-2.1.0 (>= 2.1.0+dfsg), libjpeg62 (>= 6b1), libmysqlclient16 (>= 5.1.21-1), libpng12-0 (>= 1.2.13-4), libpq5 (>= 8.4~0cvs20090328), libx11-6, libxpm4, zlib1g (>= 1:1.1.4), emboss-data (= 6.3.1-6)
Recommends: primer3, dialign
Suggests: emboss-doc, emboss-test, embassy, clustalw
Description: the european molecular biology open software suite
EMBOSS is a free Open Source software analysis package specially developed for
the needs of the molecular biology (e.g. EMBnet) user community. The software
automatically copes with data in a variety of formats and even allows
transparent retrieval of sequence data from the web. Also, as extensive
libraries are provided with the package, it is a platform to allow other
scientists to develop and release software in true open source spirit. EMBOSS
also integrates a range of currently available packages and tools for sequence
analysis into a seamless whole. EMBOSS breaks the historical trend towards
commercial software packages.
Homepage: http://emboss.sourceforge.net
我的问题是： 1）我如何知道当前安装的软件包版本来自哪个发行版（稳定、测试、不稳定、实验）？我如何在命令中引用它（例如在dpkg -L）？ 2) aptitude 命令 (show和search) 如何选择，它们应该报告哪个版本的包？为什么show和的算法search不同？
PS 请不要回答说创建混合发行版是一种不好的做法。我完全同意，但仍然必须处理那台机器。
答案1
apt-cache policy packagename_here可以告诉您哪个版本的包在哪个存储库中可用。