我需要安装 python-dev 才能安装另一个应用程序，但是当我这样做时，sudo apt-get install python-dev我得到：The following packages have unmet dependencies:带有依赖项列表。所以我添加它们直到不再有依赖项，将命令行保留为：sudo apt-get install python-dev libpython2.7-dev python2.7-dev libexpat1-dev libexpat1。
之后我得到：
The following packages have unmet dependencies:
libexpat1-dev : Depends: libexpat1 (= 2.1.0-6+b3) but 2.1.0-6+deb8u1 is to be installed
E: Unable to correct problems, you have held broken packages.
我打开 Synaptic 并搜索损坏的软件包，但没有找到。我还尝试使用 aptitude 而不是 apt-get：
The following NEW packages will be installed:
libexpat1-dev{ab} libpython-dev{a} libpython2.7-dev{a} python-dev
python2.7-dev{a}
0 packages upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/19.0 MB of archives. After unpacking 31.6 MB will be used.
The following packages have unmet dependencies:
libexpat1-dev : Depends: libexpat1 (= 2.1.0-6+b3) but 2.1.0-6+deb8u1 is installed.
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) libexpat1-dev [Not Installed]
2) libpython-dev [Not Installed]
3) libpython2.7-dev [Not Installed]
4) python-dev [Not Installed]
5) python2.7-dev [Not Installed]
Accept this solution? [Y/n/q/?]
到目前为止一切顺利（我认为），所以我按了“Y”，但它列出了很多要删除的软件包并要求我继续。由于我对此有疑问，所以我按了“n”，但现在当我再次复制建议删除的包时，它什么也没做：
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.
任何帮助将不胜感激。提前致谢。
编辑：
现在我正在使用本地存储库，因为我在连接到 debian ftp 时遇到问题（可能是因为网络管理员或代理）。所以我的sources.lst是：
#deb http://ftp.debian.org/debian/ jessie main contrib non-free
#deb-src http://ftp.debian.org/debian/ jessie main contrib non-free
#deb http://security.debian.org/ jessie/updates main contrib non-free
#deb-src http://security.debian.org/ jessie/updates main contrib non-free
# jessie-updates, previously known as 'volatile'
# A network mirror was not selected during install. The following entries
# are provided as examples, but you should amend them as appropriate
# for your mirror of choice.
#
#deb http://ftp.debian.org/debian/ jessie-updates main contrib non-free
#deb-src http://ftp.debian.org/debian/ jessie-updates main contrib non-free
##Local Repository
deb file:/media/ramon-debian/JimiHendrix/debian8repo/debian jessie main contrib non-free
deb file:/media/ramon-debian/JimiHendrix/debian8repo/debian stable main contrib non-free
答案1
您使用的存储库有问题。
https://tracker.debian.org/pkg/expat显示在 Debian 中，没有软件包libexpat1_2.1.0-6+b3...
使用 删除 apt 缓存rm -rf /var/lib/apt/lists/*，然后apt-get update再次删除。如果您的本地镜像正常，您应该有一个可用软件包的工作（一致）列表。如果没有，那么本地存储库已损坏......
答案2
问题解决了！我libexpat1_2.1.0-7_amd64.deb从libexpat1-dev_2.1.0-7_amd64.deb链接下载了软件包@Jan 发布并安装它们dpkg -i package.deb。
答案3
使用该aptitude工具 - 您会经常看到此建议，但没有说明。我在 GNU Radio PyBOMBS 构建（在 Raspberry Pi 3b 上，FWIW）上遇到了类似的问题，无论改变多少镜子、rm -rf /var/lib/apt/lists/*或apt-get clean都无法解决。
如果你的镜像有目标包，aptitude我的修复方法是否定正如您所经历的，第一个解决方案什么也没做。然后，第二个解决方案是降级，安装了所需的依赖项！
我会得到：
libevent-dev : Depends: libevent-2.0-5 (= 2.0.21-stable-2) but 2.0.21-stable-2+deb8u1 is to be installed
这是我的解决方案（对于 libevent-dev，但应该适用于 libexpat1-dev）：
# aptitude install libevent-dev
The following NEW packages will be installed:
libevent-core-2.0-5{a} libevent-dev{b} libevent-extra-2.0-5{a} libevent-openssl-2.0-5{a}
libevent-pthreads-2.0-5{a}
0 packages upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 506 kB of archives. After unpacking 1586 kB will be used.
The following packages have unmet dependencies:
libevent-dev : Depends: libevent-2.0-5 (= 2.0.21-stable-2) but 2.0.21-stable-2+deb8u1 is installed.
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) libevent-dev [Not Installed]
Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:
Downgrade the following packages:
1) libevent-2.0-5 [2.0.21-stable-2+deb8u1 (now) -> 2.0.21-stable-2 (stable)]
Accept this solution? [Y/n/q/?] y
The following packages will be DOWNGRADED:
libevent-2.0-5
The following NEW packages will be installed:
libevent-core-2.0-5{a} libevent-dev libevent-extra-2.0-5{a} libevent-openssl-2.0-5{a}
libevent-pthreads-2.0-5{a}
0 packages upgraded, 5 newly installed, 1 downgraded, 0 to remove and 0 not upgraded.
Need to get 641 kB of archives. After unpacking 1552 kB will be used.
Do you want to continue? [Y/n/?] y
之后，我可以恢复 PyBOMBS 构建并满足依赖关系（好吧，在对 libboost-dev 进行类似的修复之后......）。