Is it possible to build an up-to-date version of the g++ (14/13) on Raspberry Pi running Debian 12 arm64?

Question

I am puzzled. There is seemingly no newer Debian image for Raspberry Pi than the current stable version 12 (bookworm). I have downloaded and installed it just when it went out without issues, I remember. Link to all tested images here. My Pi's HW is 4 (8GB). Just to be clear, I am all Ok with Debian's aim to be rock-stable. Just one thing, if I may poke.

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I wonder if it is possible to build an up-to-date version of the g++ (14) on my arm64 Raspberry Pi running Debian 12? (Today, I somewhat needed it, but found out, an older g++-12 available only, it caused me only minor trouble this time.)

And if yes, how would I proceed exactly? I have no clue.

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Here is what g++ versions I found available on Linux Mint 22 (based on Ubuntu Noble), i.e. version 10+:

$ apt-cache policy g++-1[0-9] | grep -A 2 '^g++-1'

g++-10:
  Installed: (none)
  Candidate: 10.5.0-4ubuntu2
--
g++-11:
  Installed: (none)
  Candidate: 11.4.0-9ubuntu1
--
g++-12:
  Installed: 12.3.0-17ubuntu1
  Candidate: 12.3.0-17ubuntu1
--
g++-13:
  Installed: 13.3.0-6ubuntu2~24.04
  Candidate: 13.3.0-6ubuntu2~24.04
--
g++-14:
  Installed: 14.2.0-4ubuntu2~24.04
  Candidate: 14.2.0-4ubuntu2~24.04

For reference, here are currently available versions on Pi's Debian 12, i.e. versions 10+, as above:

$ apt-cache policy g++-1[0-9] | grep -A 2 '^g++-1'

g++-10:
  Installed: (none)
  Candidate: (none)
--
g++-11:
  Installed: (none)
  Candidate: 11.3.0-12
--
g++-12:
  Installed: 12.2.0-14
  Candidate: 12.2.0-14
--
g++-13:
  Installed: (none)
  Candidate: (none)

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Nope, no sign of g++-14, not even g++-13 available (yet). So, my question above stands. Thank you in advance.

Answer 1

Warning

@StephenKitt points out that the below is a dangerous operation, as you can end up with a broken system (the VM I tried this on is fine, but that wasn't an arm64 VM nor had any graphical frontend installed).

Your alternative is to get the .dsc file from packages.debian.org's trixie gcc 14, and then build that using dpkg-buildpackage. The instructions for GCC12 on Ubuntu 20.04 I wrote in this answer would solve your issue as well, but would require compiling from source.

Main text

Debian can let you set up "mixed" package sources, where you only pull in packages from the "newer" distro release when explicitly asked to/strictly necessary.

For that, you'd

1. add a trixie (current testing release of debian) repo
2. tell apt that it shouldn't use that by default
3. explicitly install gcc from that repo

1. add a trixie (current testing release of debian) repo

copy the current repo specification

sudo cp /etc/apt/sources.list.d/debian.sources /etc/apt/sources.list.d/triixie.sources

and modify pixie.sources to only list trixie; it should be, afterwards:

Types: deb
URIs: http://deb.debian.org/debian
Suites: trixie
Components: main
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg

2. tell apt that it shouldn't use that by default

create a file nvim /etc/apt/preferences.d/99debian-trixie, containing:

Package: *
Pin: release a=testing
Pin-Priority: 100

Test that this did work:

apt update
apt-cache policy
## This should now list the new trixie repository, at priority 100,
## and the default bullseye repo should still be at priority 500
apt-cache policy gcc
## Should now list GCC 14 from trixie as low-priority alternative to
## the default gcc.

3. explicitly install gcc from that repo

(and while we're at it, the usual build tools also in their more modern trixie version)

apt install -t trixie gcc g++ gdb cmake clang-format