由于某些我无法解释的原因（我想可能是因为我很笨），我从 Debian 源安装了软件包。我使用 Ubuntu 18.04。
我想修复我的错误并降级到 Ubuntu 软件包。我所做的是dpkg -l | grep -v ubuntu | grep deb列出具有“deb”版本而不是“ubuntu”的软件包。例如，我能够将 systemd 从 241 降级到 237。
但是，有些软件包不会接受降级，例如，除非我删除大量软件包（其中一些是关键软件包），否则 perl 不会降级，因此我不能接受这一点。例如：
root@KLK876:/etc/apt/preferences.d# apt-cache policy perl
perl:
Installed: 5.28.1-6+deb10u1
Candidate: 5.28.1-6+deb10u1
Version table:
*** 5.28.1-6+deb10u1 100
100 /var/lib/dpkg/status
5.26.1-6ubuntu0.5 500
500 mirror://mirrors.ubuntu.com/mirrors.txt bionic-updates/main amd64 Packages
500 mirror://mirrors.ubuntu.com/mirrors.txt bionic-security/main amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
5.26.1-6 500
500 mirror://mirrors.ubuntu.com/mirrors.txt bionic/main amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
所以我尝试恢复到 ubuntu 版本：
root@KLK876:/etc/apt/preferences.d# aptitude install perl=5.26.1-6ubuntu0.5
The following packages will be DOWNGRADED:
perl{b}
0 packages upgraded, 0 newly installed, 1 downgraded, 0 to remove and 0 not upgraded.
Need to get 201 kB of archives. After unpacking 7168 B will be freed.
The following packages have unmet dependencies:
perl-base : Breaks: perl (< 5.28.1~) but 5.26.1-6ubuntu0.5 is to be installed
libnet-libidn-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libb-hooks-op-check-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libnet-ssleay-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
liblist-moreutils-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libsereal-encoder-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libvariable-magic-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libdevel-callchecker-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libdbi-perl : Depends: perl (>= 5.28.1-6+deb10u1) but 5.26.1-6ubuntu0.5 is to be installed
perl-modules-5.28 : Breaks: perl (< 5.28.1~) but 5.26.1-6ubuntu0.5 is to be installed
libfcgi-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libsnmp-perl : Depends: perl (>= 5.28.1-6) but 5.26.1-6ubuntu0.5 is to be installed
texinfo : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libclass-c3-xs-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libpackage-stash-xs-perl : Depends: perl (>= 5.28.1-3) but 5.26.1-6ubuntu0.5 is to be installed
libperlio-gzip-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libdevel-lexalias-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libsub-identify-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libclass-xsaccessor-perl : Depends: perl (>= 5.28.1-1) but 5.26.1-6ubuntu0.5 is to be installed
libparams-util-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libposix-strptime-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libdevel-caller-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libterm-readkey-perl : Depends: perl (>= 5.28.1-3) but 5.26.1-6ubuntu0.5 is to be installed
libunicode-utf8-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libfile-fcntllock-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libcairo-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libparams-classify-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libclone-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libsub-name-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libunicode-linebreak-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libnet-dbus-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libnet-dns-sec-perl : Depends: perl (>= 5.28.1-3) but 5.26.1-6ubuntu0.5 is to be installed
libyaml-libyaml-perl : Depends: perl (>= 5.28.1-3) but 5.26.1-6ubuntu0.5 is to be installed
libglib-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libio-pty-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libxml-libxml-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libpadwalker-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libmoose-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libemail-address-xs-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libsocket6-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libdbd-mysql-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libcairo-gobject-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
perl : Depends: perl-base (= 5.26.1-6ubuntu0.5) but 5.28.1-6+deb10u1 is installed
libxml-parser-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libglib-object-introspection-perl : Depends: perl (>= 5.28.1-4) but 5.26.1-6ubuntu0.5 is to be installed
libsereal-decoder-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libhtml-parser-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libalgorithm-diff-xs-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
libperl-dev : Depends: perl:any (= 5.28.1-6+deb10u1) which is a virtual package, provided by:
- perl (5.28.1-6+deb10u1), but 5.26.1-6ubuntu0.5 is to be installed
- perl:i386 (5.26.1-6ubuntu0.5), but it is not going to be installed
- perl (5.26.1-6ubuntu0.5), but 5.26.1-6ubuntu0.5 is to be installed
- perl:i386 (5.26.1-6), but it is not going to be installed
- perl (5.26.1-6), but 5.26.1-6ubuntu0.5 is to be installed
libclass-load-xs-perl : Depends: perl (>= 5.28.0-3) but 5.26.1-6ubuntu0.5 is to be installed
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) perl [5.28.1-6+deb10u1 (now)]
Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:
Remove the following packages:
1) apache2 [2.4.38-3+deb10u4 (now)]
2) apache2-bin [2.4.38-3+deb10u4 (now)]
3) apt-file [3.2.2 (now)]
4) apt-rdepends [1.3.0-6 (bionic, now)]
5) autoconf [2.69-11.1 (now)]
6) automake [1:1.16.1-4 (now)]
7) build-essential [12.4ubuntu1 (bionic, now)]
8) cloc [1.74-1 (bionic, now)]
9) command-not-found [18.04.5-1 (now)]
10) debhelper [12.1.1ubuntu1~ubuntu18.04.1 (bionic-backports, now)]
11) dh-autoreconf [19 (now)]
12) dh-strip-nondeterminism [1.8.0-1 (now)]
13) dkms [2.3-3ubuntu9.7+elementary11~ubuntu5.0.1 (bionic, now)]
14) doc-base [0.10.9 (now)]
15) dpkg-dev [1.19.7 (now)]
16) git [1:2.20.1-2+deb10u3 (now)]
17) gnome-user-share [3.28.0-2 (now)]
18) intltool-debian [0.35.0+20060710.5 (now)]
19) libalgorithm-c3-perl [0.10-1 (bionic, now)]
20) libalgorithm-diff-perl [1.19.03-2 (now)]
21) libalgorithm-diff-xs-perl [0.04-5+b1 (now)]
22) libalgorithm-merge-perl [0.08-3 (bionic, now)]
23) libapache2-mod-dnssd [0.6-3.2 (bionic, now)]
24) libapache2-mod-php7.4 [7.4.15-1+ubuntu18.04.1+deb.sury.org+1 (bionic, now)]
25) libarchive-cpio-perl [0.10-1 (bionic, now)]
26) libarchive-zip-perl [1.64-1 (now)]
27) libasync-mergepoint-perl [0.04-2 (bionic, now)]
28) libauthen-sasl-perl [2.1600-1 (bionic, now)]
29) libb-hooks-endofscope-perl [0.24-1 (now)]
30) libb-hooks-op-check-perl [0.22-1+b1 (now)]
31) libcairo-gobject-perl [1.004-3+b1 (now)]
32) libcairo-perl [1.106-3+b1 (now)]
33) libcapture-tiny-perl [0.48-1 (bionic, now)]
34) libcgi-fast-perl [1:2.15-1 (now)]
35) libcgi-pm-perl [4.47-1 (now)]
36) libclass-accessor-perl [0.51-1 (bionic, now)]
37) libclass-c3-perl [0.34-1 (now)]
38) libclass-c3-xs-perl [0.14-1+b3 (now)]
39) libclass-load-perl [0.25-1 (now)]
40) libclass-load-xs-perl [0.10-1+b3 (now)]
41) libclass-method-modifiers-perl [2.13-1 (now)]
42) libclass-tiny-perl [1.006-1 (bionic, now)]
43) libclass-xsaccessor-perl [1.19-3+b2 (now)]
44) libclone-perl [0.41-1+b1 (now)]
45) libconvert-binhex-perl [1.125-1 (bionic, now)]
46) libdata-dump-perl [1.23-1 (bionic, now)]
47) libdata-optlist-perl [0.110-1 (bionic, now)]
48) libdbd-mysql-perl [4.050-2 (now)]
49) libdbi-perl [1.642-1+deb10u1 (now)]
50) libdbus-1-dev [1.12.2-1ubuntu1.2 (bionic-security, bionic-updates, now)]
51) libdevel-callchecker-perl [0.008-1 (now)]
52) libdevel-caller-perl [2.06-2+b1 (now)]
53) libdevel-globaldestruction-perl [0.14-1 (bionic, now)]
54) libdevel-lexalias-perl [0.05-2+b1 (now)]
55) libdevel-overloadinfo-perl [0.005-1 (now)]
56) libdevel-partialdump-perl [0.20-1 (bionic, now)]
57) libdevel-stacktrace-perl [2.0400-1 (now)]
58) libdigest-bubblebabble-perl [0.02-2 (bionic, now)]
59) libdigest-hmac-perl [1.03+dfsg-2 (now)]
60) libdist-checkconflicts-perl [0.11-1 (bionic, now)]
61) libdpkg-perl [1.19.7 (now)]
62) libdynaloader-functions-perl [0.003-1 (bionic, now)]
63) libemail-abstract-perl [3.008-2 (now)]
64) libemail-address-xs-perl [1.04-1+b1 (now)]
65) libemail-date-format-perl [1.005-1 (bionic, now)]
66) libemail-foldertype-perl [0.813-1.2 (bionic, now)]
67) libemail-localdelivery-perl [1.200-1 (bionic, now)]
68) libemail-messageid-perl [1.406-1 (bionic, now)]
69) libemail-mime-contenttype-perl [1.022-1 (bionic, now)]
70) libemail-mime-encodings-perl [1.315-2 (bionic, now)]
[...]
270) aptitude recommends libparse-debianchangelog-perl
271) libnet-dns-perl recommends libdigest-bubblebabble-perl
272) libnet-dns-perl recommends libnet-libidn-perl
273) libio-socket-ssl-perl recommends libnet-libidn-perl | libnet-idn-encode-perl | liburi-perl
274) libhtml-tree-perl recommends libhtml-format-perl
275) dpkg-dev recommends libalgorithm-merge-perl
276) libimage-exiftool-perl recommends libposix-strptime-perl
[...]
296) libwww-perl recommends libhtml-form-perl
297) libwww-perl recommends libhtml-format-perl
298) libwww-perl recommends libhttp-daemon-perl
299) libwww-perl recommends libmailtools-perl
300) libfile-stripnondeterminism-perl recommends libarchive-cpio-perl
301) libxml-sax-perl recommends libxml-sax-expat-perl
302) libpackage-stash-perl recommends libpackage-stash-xs-perl
Accept this solution? [Y/n/q/?] q
Abandoning all efforts to resolve these dependencies.
Abort.
如您所见，所提出的解决方案是不可接受的。我按了“n”多次，但没有提供任何解决方案，导致 perl 及其所有依赖项降级，没有任何重大删除或未满足的依赖项。
我列出了“deb”版本的所有软件包，并要求 aptitude 安装它们的“ubuntu”对应版本，但结果是一样的，aptitude 要么放弃，要么给出不必要的解决方案（删除太多软件包或什么也不做）。
我怎样才能安全地改正我的错误？
答案1
我的回答是基于你使用的是 ubuntu bionic 作为操作系统
这并不容易。首先备份重要数据。删除您自己所做的任何配置；我的意思是
500 镜像://mirrors.ubuntu.com/mirrors.txt bionic-updates/main amd64 软件包 500 镜像://mirrors.ubuntu.com/mirrors.txt bionic-security/main amd64 软件包
当然，删除 debian buster 源。如果集成了 bionc-backports，也可以创建
/etc/apt/preferences.d/ubuntu.pref
内容如下。我们用origin来尝试一下。
Package: *
Pin: origin us.archive.ubuntu.com
Pin-Priority: 1001
Package: *
Pin: origin security.ubuntu.com
Pin-Priority: 1001
#下一个是只有当你有合作伙伴在你的资源中
Package: *
Pin : release v=18.04,o=Canonical
Pin-Priority: 1001
刷新
sudo apt update
那么你可以先进行模拟。
apt -s full-upgrade
请注意这是否可行。
答案2
@nobody 的回答有助于修复一些软件包，但不是全部。
我注意到所有 debian 软件包都是使用 /var/lib/dpkg/status 安装的，优先级为 100，而 ubuntu 软件包都是从在线源安装的，优先级为 500。
因此，我列出了所有使用 100 版本而不是 500 版本的软件包，并强制将它们全部（几乎一个接一个，总共约 1200 个）安装到 ubuntu 版本，有时会删除仅限 debian 的软件包。
这花了我将近一天的时间，但最终所有软件包都恢复到了 ubuntu 版本并且一切恢复正常。
如果有人感兴趣的话，以下是我识别破损包裹的方法：
#!/bin/bash
dpkg -l \
| awk '/^ii/{print $2}' \
| while read p
do
pol=$(apt-cache policy $p)
ko=$(echo "$pol" | grep -P '\*{3} .* 100$')
if [ "$ko" != "" ]; then
echo $p=$(echo "$pol" | awk '/500$/{print $1;exit}')
fi
done
我将此脚本的输出保存到一个文件中，然后从此文件中随机挑选 10 或 20 个并使用aptitude install（如aptitude install $(shuf -n 10 /tmp/pkg | tr \\n \ )）并使用在发生冲突时提出各种解决方案的强大功能aptitude。我总是选择仅降级或建议降级+删除 debian 专用软件包的选项。
我完成了清理我的来源和偏好设置的工作，然后运行apt update，apt upgrade然后apt full-upgrade一切都修复了。
这会教会我！谢谢你的帮助。