我不知道为什么，我无法更新我的 gcc
root@server:~# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.4-2ubuntu1~14.04.1' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
尝试命令
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install g++-4.9
有日志：
root@server:~# sudo add-apt-repository 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 adding it
gpg: keyring `/tmp/tmpi_ap8pke/secring.gpg' created
gpg: keyring `/tmp/tmpi_ap8pke/pubring.gpg' created
gpg: requesting key BA9EF27F from hkp server keyserver.ubuntu.com
gpg: /tmp/tmpi_ap8pke/trustdb.gpg: trustdb created
gpg: key BA9EF27F: public key "Launchpad Toolchain builds" imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
OK
root@server:~# sudo apt-get update
Hit http://security.ubuntu.com trusty-security InRelease
Ign http://archive.ubuntu.com trusty InRelease
Ign http://archive.canonical.com trusty InRelease
Get:1 http://ppa.launchpad.net trusty InRelease [15.5 kB]
Get:2 http://security.ubuntu.com trusty-security/main amd64 Packages [493 kB]
Hit http://archive.ubuntu.com trusty-updates InRelease
Get:3 http://archive.canonical.com trusty Release.gpg [933 B]
E: The method driver /usr/lib/apt/methods/https could not be found.
N: Is the package apt-transport-https installed?
root@server:~# sudo apt-get install g++-4.9
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package g++-4.9
E: Couldn't find any package by regex 'g++-4.9'
root@server:~#
再次检查 gcc 版本。
root@server:~# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.4-2ubuntu1~14.04.1' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
root@server:~#
答案1
工具链存储库需要 https 访问，因此由于错误
E: The method driver /usr/lib/apt/methods/https could not be found.
即使您已成功添加存储库，但您的软件包目录仍未更新。
您可以在以下网址找到一些修复错误的建议“找不到方法驱动程序 /usr/lib/apt/methods/https”更新错误- 如果你很幸运（意味着普通的 http 方法也没有损坏），它应该像安装（或可能重新安装）相关包一样简单
sudo apt-get install apt-transport-https