我正在按照docker文档中的说明进行操作从存储库安装到 ubuntu 20.04。我以前曾为公司存储库做过这种事情，但从来没有遇到过这样的问题。这些是我运行的命令，它建议：
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
执行此命令时没有错误，并且似乎在命令显示的路径中创建了文件。然后我运行：
echo \
"deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
这似乎也在例外文件中创建了预期的字符串。当我 cat 时，/etc/apt/sources.list.d/docker.list我得到：
deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu focal stable
我相信这是意料之中的。没有换行符。然后我运行sudo apt update，这是该过程的下一步，它返回以下错误：
E: Conflicting values set for option Signed-By regarding source https://download.docker.com/linux/ubuntu/ focal: /usr/share/keyrings/docker-archive-keyring.gpg !=
E: The list of sources could not be read.
因此，我认为他们的设置存在某种错误配置。除非 curl 命令输入了错误的键，否则我看不出这怎么会有冲突的值，但我也不太了解 apt 的内部工作原理。如果这是我这边的问题，我可以或多或少轻松修复，那将是好消息。
编辑/etc/apt/sources.list以下是我的系统上的内容：
# deb cdrom:[Kubuntu 20.04 LTS _Focal Fossa_ - Release amd64 (20200423)]/ focal main multiverse restricted universe
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://us.archive.ubuntu.com/ubuntu/ focal main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://us.archive.ubuntu.com/ubuntu/ focal-updates main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ focal universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal universe
deb http://us.archive.ubuntu.com/ubuntu/ focal-updates universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://us.archive.ubuntu.com/ubuntu/ focal multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://us.archive.ubuntu.com/ubuntu/ focal-updates multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu focal partner
deb http://security.ubuntu.com/ubuntu focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://security.ubuntu.com/ubuntu focal-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://security.ubuntu.com/ubuntu focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse
# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
# deb http://repo.kfocus.org/ubuntu focal main
# deb-src http://repo.kfocus.org/ubuntu focal main
答案1
删除此文件后，我能够让 apt 再次工作：/etc/apt/sources.list.d/docker.list
答案2
在我的例子中，我在/etc/apt/sources.list.d名为“name”的文件下找到了另一个文件focal_docker.list，该文件具有完全相同的内容，但没有signed-by=/usr/share/keyrings/docker-archive-keyring.gpg导致此冲突的部分。我删除了这个文件，之后一切都正常了。