如何在Ubuntu18.04.01LTS中正确地将gcc7.3升级到gcc8？

Question

In我的Ubuntu18.04LTS：

marco@PC:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.1 LTS
Release:        18.04
Codename:       bionic

I有gcc版本7.3.0:

marco@PC:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu    
7.3.0-21ubuntu1~16.04' --with-bugurl=file:///usr/share/doc/gcc-
7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++
--prefix=/usr --with-gcc-major-version-only --program-suffix=-7 
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-
id --libexecdir=/usr/lib --without-included-gettext --enable-
threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-
clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-
default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-
verify --enable-libmpx --enable-plugin --with-system-zlib --with-target-
system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror 
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 
--enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none 
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu 
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.3.0 (Ubuntu 7.3.0-21ubuntu1~16.04)

And我想安装gcc-8:

marco@PC:~$ sudo apt-get install gcc-8
[sudo] password for marco:
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:
 gcc-8 : Depends: cpp-8 (= 8.1.0-1ubuntu1) but it is not going to be   
installed
         Depends: gcc-8-base (= 8.1.0-1ubuntu1) but 8.1.0-5ubuntu1~16.04 
is to be installed
         Depends: libgcc-8-dev (= 8.1.0-1ubuntu1) but it is not going to 
be installed
E: Unable to correct problems, you have held broken packages.

遵循这里找到的提示，askUbuntu:无法纠正问题，您持有了损坏的包

marco@PC:~$ sudo apt-get update
[sudo] password for marco:
Hit:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:2 http://cz.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Hit:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease
Fetched 88.7 kB in 1s (107 kB/s)
Reading package lists... Done
marco@PC:~$ sudo apt-get autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
marco@PC:~$ dpkg --get-selections | grep hold
marco@PC:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
marco@PC:~$ sudo apt-get update
Hit:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:2 http://cz.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Hit:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease
Fetched 88.7 kB in 1s (123 kB/s)
Reading package lists... Done

然后，我检查了使用的PPA存储库，如建议的那样：

marco@PC:~$ apt-cache policy gcc-8 cpp-8 libgcc-8-dev
gcc-8:
  Installed: (none)
  Candidate: 8.1.0-1ubuntu1
  Version table:
     8.1.0-1ubuntu1 500
        500 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu    
bionic/main amd64 Packages
     8-20180414-1ubuntu2 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64  
Packages
cpp-8:
  Installed: (none)
  Candidate: 8.1.0-1ubuntu1
  Version table:
     8.1.0-1ubuntu1 500
        500 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu  
bionic/main amd64 Packages
     8-20180414-1ubuntu2 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64   
Packages
libgcc-8-dev:
  Installed: (none)
  Candidate: 8.1.0-1ubuntu1
  Version table:
     8.1.0-1ubuntu1 500
        500 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu 
bionic/main amd64 Packages
     8-20180414-1ubuntu2 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64      
        Packages

然后，我删除了/test：

sudo add-apt-repository --remove ppa:ubuntu-toolchain-r/test
 Toolchain test builds; see https://wiki.ubuntu.com/ToolChain
 More info: https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test
Press [ENTER] to continue or Ctrl-c to cancel removing it.

但问题仍然存在：

marco@PC:~$ sudo apt-get install gcc-8
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:
 gcc-8 : Depends: cpp-8 (= 8-20180414-1ubuntu2) but it is not going to be 
installed
         Depends: gcc-8-base (= 8-20180414-1ubuntu2) but 8.1.0-5ubuntu1~16.04  
is to be installed
         Depends: libgcc-8-dev (= 8-20180414-1ubuntu2) but it is not going to 
be installed
E: Unable to correct problems, you have held broken packages.

marco@PC:~$ sudo apt-get install cpp-8
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:
 cpp-8 : Depends: gcc-8-base (= 8.1.0-1ubuntu1) but 8.1.0-5ubuntu1~16.04 
 is to be installed
E: Unable to correct problems, you have held broken packages.

marco@PC:~$ sudo apt-get install gcc-8-base
Reading package lists... Done
Building dependency tree
Reading state information... Done
gcc-8-base is already the newest version (8.1.0-5ubuntu1~16.04).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

marco@PC:~$ sudo apt-get install libgcc-8-dev
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:
 libgcc-8-dev : Depends: gcc-8-base (= 8.1.0-1ubuntu1) but   
8.1.0-5ubuntu1~16.04 is to be installed
                Depends: libasan5 (>= 8.1.0-1ubuntu1) but it is not going
 to be installed
                Depends: libubsan1 (>= 8.1.0-1ubuntu1) but it is not 
 going to be installed
E: Unable to correct problems, you have held broken packages.

marco@PC:~$ sudo apt-get install libasan5
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:
 libasan5 : Depends: gcc-8-base (= 8.1.0-1ubuntu1) but   
 8.1.0-5ubuntu1~16.04 is to be installed
E: Unable to correct problems, you have held broken packages.

marco@PC:~$ sudo apt-get install libubsan1
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:
 libubsan1 : Depends: gcc-8-base (= 8.1.0-1ubuntu1) but     
 8.1.0-5ubuntu1~16.04 is to be installed
E: Unable to correct problems, you have held broken packages.

所以..。看来，为了安装gcc-8，我必须安装其他的软件包依赖于其他软件包，这取决于自己的gcc-8-基地，这已经被正确安装。

上面写着“破碎的包裹”。那么如何解决这个问题呢？期待您的善意提示和帮助。马可

更新：

marco@PC:~$ sudo apt-get install ppa-purge
Reading package lists... Done
Building dependency tree
Reading state information... Done
ppa-purge is already the newest version (0.2.8+bzr63).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

marco@PC:~$ sudo ppa-purge ppa:ubuntu-toolchain-r/test
Updating packages lists
PPA to be removed: ubuntu-toolchain-r test
Warning:  Could not find package list for PPA: ubuntu-toolchain-r test

marco@PC:~$ sudo apt-get update
Hit:1 http://cz.archive.ubuntu.com/ubuntu bionic InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done

marco@PC:~$ sudo apt install gcc-8-base gcc-8 cpp-8 libgcc-8-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
gcc-8-base is already the newest version (8.1.0-5ubuntu1~16.04).
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:
 cpp-8 : Depends: gcc-8-base (= 8-20180414-1ubuntu2) but 8.1.0-5ubuntu1~16.04  
 is to be installed
 gcc-8 : Depends: gcc-8-base (= 8-20180414-1ubuntu2) but 8.1.0-5ubuntu1~16.04
 is to be installed
 libgcc-8-dev : Depends: gcc-8-base (= 8-20180414-1ubuntu2) but    
 8.1.0-5ubuntu1~16.04 is to be installed
                 Depends: libasan5 (>= 8-20180414-1ubuntu2) but it is not
                  going to be installed
                 Depends: libubsan1 (>= 8-20180414-1ubuntu2) but it is not 
                  going to be installed
 E: Unable to correct problems, you have held broken packages.

在安装智能之后，我遵循了智能所指示的建议。现在我遇到了这样的情况：

marco@PC:~$ sudo update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

  Selection    Path            Priority   Status
------------------------------------------------------------
* 0            /usr/bin/gcc-7   700       auto mode
  1            /usr/bin/gcc-7   700       manual mode
  2            /usr/bin/gcc-8   80        manual mode


 marco@PC:~$ g++ -std=c++17 HelloWorld.cpp -oHelloWorld
marco@PC:~$ ./HelloWorld
Hello World!

如果我选择使用gcc-8：

marco@PC:~$ sudo update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

  Selection    Path            Priority   Status
------------------------------------------------------------
* 0            /usr/bin/gcc-7   700       auto mode
  1            /usr/bin/gcc-7   700       manual mode
  2            /usr/bin/gcc-8   80        manual mode

Press  to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/bin/gcc-8 to provide /usr/bin/gcc (gcc) in 
manual mode
update-alternatives: warning: skip creation of /usr/bin/g++ because 
associated file /usr/bin/g++-8 (of link group gcc) doesn't exist


marco@PC:~$ sudo aptitude install g++-8
The following NEW packages will be installed:
  g++-8 libstdc++-8-dev{a}
0 packages upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 9,623 kB of archives. After unpacking 43.7 MB will be used.
Do you want to continue? [Y/n/?] Y
Get: 1 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 libstdc++-8-
dev amd64 8-20180414-1ubuntu2 [1,536 kB]
Get: 2 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 g++-8 amd64 
8-20180414-1ubuntu2 [8,088 kB]
Fetched 9,623 kB in 1s (7,165 kB/s)
Selecting previously unselected package libstdc++-8-dev:amd64.
(Reading database ... 92421 files and directories currently installed.)
Preparing to unpack .../libstdc++-8-dev_8-20180414-1ubuntu2_amd64.deb ...
Unpacking libstdc++-8-dev:amd64 (8-20180414-1ubuntu2) ...
Selecting previously unselected package g++-8.
Preparing to unpack .../g++-8_8-20180414-1ubuntu2_amd64.deb ...
Unpacking g++-8 (8-20180414-1ubuntu2) ...
Setting up libstdc++-8-dev:amd64 (8-20180414-1ubuntu2) ...
Setting up g++-8 (8-20180414-1ubuntu2) ...
Processing triggers for man-db (2.8.3-2) ...


marco@PC:~$ sudo update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

  Selection    Path            Priority   Status
------------------------------------------------------------
  0            /usr/bin/gcc-7   700       auto mode
  1            /usr/bin/gcc-7   700       manual mode
* 2            /usr/bin/gcc-8   80        manual mode

Press  to keep the current choice[*], or type selection number:
update-alternatives: warning: forcing reinstallation of alternative /usr/bin
/gcc-8 because link group gcc is broken

现在，在重新启动之后，它似乎起作用了：

marco@PC:~$ sudo update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

      Selection    Path            Priority   Status
------------------------------------------------------------
  0            /usr/bin/gcc-7   700       auto mode
  1            /usr/bin/gcc-7   700       manual mode
* 2            /usr/bin/gcc-8   80        manual mode

Press  to keep the current choice[*], or type selection number:
marco@PC:~$ g++ -std=c++17 HelloWorld.cpp -oHelloWorld
marco@PC:~$ ./HelloWorld
Hello World!

marco@PC:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu   
8-20180414-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs  
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr   
--with-gcc-major-version-only --with-as=/usr/bin/x86_64-linux-gnu-as --with- 
ld=/usr/bin/x86_64-linux-gnu-ld --program-suffix=-8 --program-prefix=x86_64-  
linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib  
--without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-
nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-
libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-
object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-
default-pie --with-system-zlib --with-target-system-zlib --enable-objc-
gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-
abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-
tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver
 --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu 
--target=x86_64-linux-gnu

Thread model: posix
gcc version 8.0.1 20180414 (experimental) [trunk revision 259383] (Ubuntu 
8-20180414-1ubuntu2)

Answer 1

来自软件源16.04的不兼容存储库(S)正在干扰Ubuntu18.04中的其他软件包的安装，并导致有关损坏包的错误消息，因此从您的软件源中删除那些使用ppa-清除的不兼容存储库。

然后，您将能够从默认的Ubuntu18.04存储库中安装所需的包。打开终端并键入：

sudo apt-get install ppa-purge
sudo apt update 
sudo apt install aptitude 
sudo aptitude install libubsan1 libasan5 libgcc-8-dev gcc-8-base gcc-8 cpp-8 g++-8 

在运行最后一个命令后，如果存在依赖问题，请遵循智能建议，因为aptitude在建议如何解决由中断的包引起的依赖问题方面有点聪明。