how to install gcc-12 on ubuntu

Question

$ sudo apt search gcc-12
Sorting... Done
Full Text Search... Done
$ uname -a
Linux Han 5.10.81.1-microsoft-standard-WSL2 #1 SMP Mon Nov 22 18:52:15 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

I am using the default sources.list file, I want to install gcc-12 but I can't find it in the mirror source, what should I do!

Baucom

Ubuntu, gcc-12 launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test → gcc overview ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g – Eldrida

@KnudLarsen gcc-12 is not referenced anywhere in your links – Laux

windows-subsystem-for-linux : There should be a gcc-12 version for Ubuntu 22.04 .... as it is available for the default Ubuntu packages.ubuntu.com/jammy/g++-12 . ..... Ubuntu 22.04 will be released tomorrow. – Eldrida

As an aside, you should not need sudo for apt search – Iterate

Answer 1

gcc-12 is not available in ubuntu 20.04, so we need to compile it from source code, here are the steps which I borrowed from this video:

• Step 1: clone gcc source code and checkout gcc-12 branch

$ git clone https://gcc.gnu.org/git/gcc.git gcc-source
$ cd gcc-source/
$ git branch -a
$ git checkout remotes/origin/releases/gcc-12

• Step 2: make another build dir

Note this is important as running ./configure from within the source directory is not supported as documented here.

$ mkdir ../gcc-12-build
$ cd ../gcc-12-build/
$ ./../gcc-source/configure --prefix=$HOME/install/gcc-12 --enable-languages=c,c++

• Step 3: installing GCC prequisites and run configure again

The missing libraries will be shown in above ./confgiure output, search and install them one by one.

$ apt-cache search MPFR
$ sudo apt-get install libmpfrc++-dev
$ apt-cache search MPC | grep dev
$ sudo apt-get install libmpc-dev
$ apt-cache search GMP | grep dev
$ sudo apt-get install libgmp-dev
$ sudo apt-get install gcc-multilib
$ ./../gcc-source/configure --prefix=$HOME/install/gcc-12 --enable-languages=c,c++

An alternartive is to run the download_prerequisites script.

$ cd ../
$ cd gcc-source/
$ ./contrib/download_prerequisites
$ ./../gcc-source/configure --prefix=$HOME/install/gcc-12 --enable-languages=c,c++

• Step 4: compile gcc-12

$ make -j16

Still flex is missing:

$ sudo apt-get install flex
$ ./../gcc-source/configure --prefix=$HOME/install/gcc-12 --enable-languages=c,c++
$ make -j16
$ make install

Another way is to use Ubuntu 22.04 where gcc-12 is available. In Ubuntu 22.04, gcc-12 can be installed with apt:

$ sudo apt install gcc-12

Faruq

I tried it on Kubuntu 20.04. Without download_prerequisites it complained about missing "isl" component. Also I needed to supply configure options --disable-multilib and --with-isl. Then build to succeed. However second build after flex installation failed with "Error 2" and it said I should "make distcean" first. Finally I tried install but it says target install is unknown. – Statocyst

Why do you do a second make after installation of flex? Why no installing flex at the beginning and then doing a single make? – Statocyst

@Statocyst In my case, in the begining when running ./../gcc-source/configure, it was not complaining missing flex, it complained until make -j16 stage. – Faruq

How add gcc-12 to alternative c and c++ compiler under linux? – Wolframite

@KhurshidNormuradov sudo update-alternatives --install /usr/bin/gcc gcc ~/install/gcc-12/bin/gcc 120 --slave /usr/bin/g++ g++ ~/install/gcc-12/bin/g++ --slave /usr/bin/gcov gcov ~/install/gcc-12/bin/gcov will do (assuming gcc-12 is installed in ~/install/gcc-12). More info can be referred from linuxize.com/post/how-to-install-gcc-compiler-on-ubuntu-18-04 – Faruq

Note for those of you building it on a VM: you need quite a lot of space. For me gcc-source folder is 1.9 GB and gcc-12-build ended up 8.2 GB. You also need sufficient swap space (see askubuntu.com/a/299441 for how to create swap files if you don’t have a swap partition) or the build might fail with signal 9. – Perdu

Easiest on Ubuntu 22.04 is: sudo apt install gcc-12 – Fusil

Answer 2

You can use Homebrew to install pre-built binaries. Follow instructions to install Homebrew at https://brew.sh/, then

brew install gcc for default GCC (currently 11) or brew install gcc@12 for gcc-12.

Note that it may compile missing dependencies.

Beautifully

Homebrew is macOS only, right? – Statocyst

No, you can also use it on Linux now. – Manvil

error: RPC failed; curl 56 GnuTLS recv error (-54): Error in the pull function. error: 1604 bytes of body are still expected fetch-pack: unexpected disconnect while reading sideband packet fatal: early EOF fatal: fetch-pack: invalid index-pack output Failed during: git fetch --force origin refs/heads/master:refs/remotes/origin/master – Almonte

Answer 3

ubuntu 22.04:

sudo apt install gcc-12

Offen

If you want to make gcc-12 the default compiler you need to change the links in /usr/bin – Gatto

askubuntu.com/questions/1500017/… – Gatto

to update the link, go to /usr/bin, then first remove the old symlink by sudo rm gcc, then create the new symlink by sudo ln -s gcc-12 gcc. Verify by gcc --version – Geary

Answer 4

I would add if you are adding for 64 bit only, you'll want to add "--disable=multilib" to the end of your configure statement.

Amadoamador

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