Kiran Shahi's questions

我正在尝试按照Jekyll on Windows 教程安装 Jekyll 。从BrightBox存储库安装 ruby​​ 有一个陡峭的过程。我触发了以下命令：

sudo apt-add-repository ppa:brightbox/ruby-ng
sudo apt-get update
sudo apt-get install ruby2.4 ruby2.4-dev build-essential dh-autoreconf

最后一个命令产生以下错误：

sudo apt-get install ruby2.4 ruby2.4-dev build-essential dh-autoreconf
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package ruby2.4
E: Couldn't find any package by glob 'ruby2.4'
E: Couldn't find any package by regex 'ruby2.4'
E: Unable to locate package ruby2.4-dev
E: Couldn't find any package by glob 'ruby2.4-dev'
E: Couldn't find any package by regex 'ruby2.4-dev' 

我该如何解决这个问题？

在 Ubuntu 17.10 上E: Package 'apache2' has no installation candidate安装 apache2 时出错。sudo apt-get install apache2这是终端上显示的消息。

sudo apt-get install apache2
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package apache2 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'apache2' has no installation candidate

命令后的消息apt-cache policy apache2。

apache2:
  Installed: (none)
  Candidate: (none)
  Version table:

egrep -v '^#|^ *$' /etc/apt/sources.list /etc/apt/sources.list.d/*.list命令后的消息

/etc/apt/sources.list.d/linuxgndu-ubuntu-sqlitebrowser-artful.list:deb http://ppa.launchpad.net/linuxgndu/sqlitebrowser/ubuntu artful main
/etc/apt/sources.list.d/mongodb-org-3.6.list:deb [arch=amd64,arm64] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.6 multiverse
/etc/apt/sources.list.d/slack.list:deb https://packagecloud.io/slacktechnologies/slack/debian/ jessie main
/etc/apt/sources.list.d/sublime-text.list:deb https://download.sublimetext.com/ apt/stable/
/etc/apt/sources.list.d/vscode.list:deb [arch=amd64] http://packages.microsoft.com/repos/vscode stable main
/etc/apt/sources.list.d/webupd8team-ubuntu-java-artful.list:deb http://ppa.launchpad.net/webupd8team/java/ubuntu artful main

我该如何解决这个问题？

使用的命令：

sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev

输出：

Reading package lists... Done
Building dependency tree
Reading state information... Done
curl is already the newest version.
curl set to manually installed.
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:
build-essential : Depends: g++ (>= 4:4.4.3) but it is not going to be installed
Depends: dpkg-dev (>= 1.13.5) but it is not going to be installed
libcurl4-openssl-dev : Depends: libcurl3 (= 7.35.0-1ubuntu2) but 7.35.0-1ubuntu2.5 is to be installed
Depends: libkrb5-dev but it is not going to be installed
Depends: libldap2-dev but it is not going to be installed
Depends: librtmp-dev but it is not going to be installed
libsqlite3-dev : Depends: libsqlite3-0 (= 3.8.2-1ubuntu2) but 3.8.2-1ubuntu2.1 is to be installed
libssl-dev : Depends: libssl1.0.0 (= 1.0.1f-1ubuntu2) but 1.0.1f-1ubuntu2.15 is to be installed
Recommends: libssl-doc but it is not going to be installed
libxml2-dev : Depends: libxml2 (= 2.9.1+dfsg1-3ubuntu4) but 2.9.1+dfsg1-3ubuntu4.4 is to be installed
sqlite3 : Depends: libsqlite3-0 (= 3.8.2-1ubuntu2) but 3.8.2-1ubuntu2.1 is to be installed
E: Unable to correct problems, you have held broken packages.

如何解决这个问题。