我目前陷入困境，无法在我的 PC 上安装 mono-devel。我已经安装了 mono 密钥环和 repo，但每当我尝试安装它时，都会出现以下情况：
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:
mono-devel : Depends: mono-runtime (>= 3.0~) but it is not going to be installed
Depends: libc6 (>= 2.31) but 2.28-10 is to be installed or
libc6.1 (>= 2.31) but it is not installable or
libc0.1 (>= 2.31) but it is not installable
Depends: libglib2.0-0 (>= 2.64.6) but 2.58.3-2+deb10u2 is to be installed
Depends: libmono-cecil-private-cil (>= 6.12.0.122) but it is not going to be installed
Depends: libmono-cecil-private-cil (< 6.12.0.123) but it is not going to be installed
Depends: libmono-codecontracts4.0-cil (>= 1.0) but it is not going to be installed
Depends: libmono-compilerservices-symbolwriter4.0-cil (>= 3.6.0) but it is not going to be installed
Depends: libmono-corlib4.5-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: libmono-peapi4.0a-cil (>= 3.2.8) but it is not going to be installed
Depends: libmono-relaxng4.0-cil (>= 2.10.1) but it is not going to be installed
Depends: libmono-security4.0-cil (>= 3.0.6) but it is not going to be installed
Depends: libmono-system-configuration-install4.0-cil (>= 1.0) but it is not going to be installed
Depends: libmono-system-configuration4.0-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: libmono-system-core4.0-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: libmono-system-data4.0-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: libmono-system-drawing4.0-cil (>= 3.0.6) but it is not going to be installed
Depends: libmono-system-io-compression-filesystem4.0-cil (>= 3.2.1) but it is not going to be installed
Depends: libmono-system-runtime-serialization4.0-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: libmono-system-runtime4.0-cil (>= 2.10.1) but it is not going to be installed
Depends: libmono-system-security4.0-cil (>= 1.0) but it is not going to be installed
Depends: libmono-system-servicemodel4.0a-cil (>= 3.2.3) but it is not going to be installed
Depends: libmono-system-web-services4.0-cil (>= 1.0) but it is not going to be installed
Depends: libmono-system-xml-linq4.0-cil (>= 3.0.6) but it is not going to be installed
Depends: libmono-system-xml4.0-cil (>= 3.12.0) but it is not going to be installed
Depends: libmono-system4.0-cil (>= 4.0.0~alpha1) but it is not going to be installed
Depends: mono-mcs (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: mono-roslyn (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: mono-gac (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: mono-xbuild (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: libmono-cil-dev (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: libmono-2.0-dev (>= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
Depends: libmono-2.0-dev (< 6.12.0.122-0xamarin1+ubuntu2004b1.1~) but it is not going to be installed
Depends: ca-certificates-mono (= 6.12.0.122-0xamarin1+ubuntu2004b1) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
请帮忙，谢谢大家。
答案1
安装为您的系统构建的版本，而不是可用的最新版本。您的系统为 20.04，尝试安装至少为 20.10 构建的软件包，但出现 libc6 错误。当您将存储库添加到安装时，它们必须是同一版本，否则将无法安装。