我們有一個 debian jessie 安裝，我們正在嘗試安裝一個jessie-backports-sloppy/ejabberd軟體包
# apt-get -t jessie-backports-sloppy install ejabberd
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:
ejabberd : Depends: erlang-asn1 (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-base (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed or
erlang-base-hipe (>= 1:19.2.1+dfsg) but it is not going to be installed
Depends: erlang-crypto (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-inets (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-mnesia (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-odbc (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-public-key (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-ssl (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-syntax-tools (>= 1:19.2.1+dfsg) but 1:17.3-dfsg-4+deb8u2 is to be installed
Depends: erlang-jiffy (>= 0.14.8) but 0.8.5+dfsg-1 is to be installed
Depends: erlang-lager (>= 3.4.2) but 2.0.3-1 is to be installed
Depends: erlang-p1-cache-tab (>= 1.0.10) but 1.0.4-2~bpo8+1 is to be installed
Depends: erlang-p1-iconv (>= 1.0.5) but 1.0.2-2~bpo8+1 is to be installed
Depends: erlang-p1-stringprep (>= 1.0.9) but 1.0.6-2~bpo8+1 is to be installed
Depends: erlang-p1-tls (>= 1.0.15) but 1.0.7-2~bpo8+1 is to be installed
Depends: erlang-p1-utils (>= 1.0.9) but 1.0.5-3~bpo8+1 is to be installed
Depends: erlang-p1-xml (>= 1.1.23) but 1.1.15-2~bpo8+1 is to be installed
Depends: erlang-p1-xmpp (>= 1.1.14) but it is not going to be installed
Depends: erlang-p1-yaml (>= 1.0.10) but 1.0.6-2~bpo8+1 is to be installed
Depends: erlang-p1-zlib (>= 1.0.2) but 1.0.1-4~bpo8+1 is to be installed
E: Unable to correct problems, you have held broken packages.
我們/etc/apt/sources.list使用以下命令啟動了兩個儲存庫：
deb http://ftp.hosteurope.de/mirror/ftp.debian.org/debian jessie-backports main contrib non-free
deb http://ftp.hosteurope.de/mirror/ftp.debian.org/debian jessie-backports-sloppy main contrib non-free
正如您在範例中看到的，其中一個套件在工作版本中可用：
# apt show erlang-asn1 -a
Package: erlang-asn1
Source: erlang
Version: 1:19.2.1+dfsg-2+deb9u1~bpo8+1
Installed-Size: 1,026 kB
Maintainer: Debian Erlang Packagers <[email protected]>
Replaces: erlang (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-base (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-base-hipe (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-dev (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-doc (>> 1:19.2.1+dfsg-999), erlang-doc (<< 1:19.2.1+dfsg), erlang-examples (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-manpages (<= 1:11.b.1-2), erlang-mode (<< 1:12.b.1-dfsg-2), erlang-nox (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-src (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1), erlang-x11 (<< 1:19.2.1+dfsg-2+deb9u1~bpo8+1)
Depends: erlang-base (= 1:19.2.1+dfsg-2+deb9u1~bpo8+1) | erlang-base-hipe (= 1:19.2.1+dfsg-2+deb9u1~bpo8+1), libc6 (>= 2.14)
Suggests: erlang, erlang-manpages, erlang-doc
Homepage: http://www.erlang.org/
Section: interpreters
Priority: optional
Download-Size: 738 kB
APT-Sources: http://ftp.hosteurope.de/mirror/ftp.debian.org/debian/ jessie-backports/main amd64 Packages
Description: Erlang/OTP modules for ASN.1 support
The Asn1 application contains modules with compile-time and run-time
support for ASN.1 in Erlang/OTP.
Package: erlang-asn1
Source: erlang
Version: 1:17.3-dfsg-4+deb8u2
Installed-Size: 1,113 kB
Maintainer: Debian Erlang Packagers <[email protected]>
Replaces: erlang (<< 1:17.3-dfsg-4+deb8u2), erlang-base (<< 1:17.3-dfsg-4+deb8u2), erlang-base-hipe (<< 1:17.3-dfsg-4+deb8u2), erlang-dev (<< 1:17.3-dfsg-4+deb8u2), erlang-doc (>> 1:17.3-dfsg-999), erlang-doc (<< 1:17.3-dfsg), erlang-examples (<< 1:17.3-dfsg-4+deb8u2), erlang-manpages (<= 1:11.b.1-2), erlang-mode (<< 1:12.b.1-dfsg-2), erlang-nox (<< 1:17.3-dfsg-4+deb8u2), erlang-src (<< 1:17.3-dfsg-4+deb8u2), erlang-x11 (<< 1:17.3-dfsg-4+deb8u2)
Depends: erlang-base (= 1:17.3-dfsg-4+deb8u2) | erlang-base-hipe (= 1:17.3-dfsg-4+deb8u2), libc6 (>= 2.14)
Suggests: erlang, erlang-manpages, erlang-doc
Homepage: http://www.erlang.org/
Section: interpreters
Priority: optional
Download-Size: 786 kB
APT-Manual-Installed: yes
APT-Sources: http://ftp.hosteurope.de/mirror/ftp.debian.org/debian/ jessie/main amd64 Packages
Description: Erlang/OTP modules for ASN.1 support
The Asn1 application contains modules with compile-time and run-time
support for ASN.1 in Erlang/OTP.
有人有解決辦法嗎？
答案1
你可能要設定固定正確地，透過將文件放入/etc/apt/preferences.d/.也許是這樣的？
# /etc/apt/preferences.d/ejabberd
Package: ejabberd*
Pin: release a=jessie-backports-sloppy
Pin-Priority:600
# /etc/apt/preferences.d/erlang
Package: erlang*
Pin: release a=jessie-backports
Pin-Priority:600