CLang Toolchain

Install Latest Version

Add APT Repository (Debian/Ubuntu)

Visit apt.llvm.org to verify the correct repository for your distribution.

Solution with sources-file

Add a source-list file llvm-toolchain.sources to the directory /etc/apt/sources.list.d/.

cat <<EOD | sudo tee /etc/apt/sources.list.d/llvm-toolchain.sources >/dev/null
Types: deb
URIs: http://apt.llvm.org/$(lsb_release -sc)
Suites: llvm-toolchain-$(lsb_release -sc)
Components: main
Architectures: $(dpkg --print-architecture)
Signed-By:
$(wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sed 's/^/ /')
EOD

Solution with list-file

For older distributions not supporting .sources files.

The repository PGP key may already be installed on desktop distributions. If not, use the following commands to add the key and repository:

sudo wget https://apt.llvm.org/llvm-snapshot.gpg.key -O /etc/apt/trusted.gpg.d/apt.llvm.org.asc
echo "deb [arch=$(dpkg --print-architecture)] http://apt.llvm.org/$(lsb_release -sc)/ llvm-toolchain-$(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/llvm-toolchain.list

Install LLVM/Clang Packages

After adding the repository, update the package list and install the desired LLVM/Clang packages:

sudo apt update
sudo apt install clang lldb lld

You can install specific versions by appending the version number (e.g., clang-18, clang-19).

Enable Unattended Upgrades

Since LLVM packages receive frequent updates, you can configure unattended upgrades for automatic updates.

Install Unattended Upgrades Package

Install the required package:

sudo apt install unattended-upgrades

Enable it using the following command:

sudo dpkg-reconfigure -plow unattended-upgrades

This modifies /etc/apt/apt.conf.d/20auto-upgrades, setting two flags:

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";

Configuration File for LLVM

Get repository information by running:

apt policy

The result will contain a section similar to:

 500 http://apt.llvm.org/jammy llvm-toolchain-jammy/main amd64 Packages
     release n=llvm-toolchain-jammy,c=main,b=amd64
     origin apt.llvm.org

Create the file /etc/apt/apt.conf.d/51unattended-upgrades-llvm with the following content:

Unattended-Upgrade::Origins-Pattern {
        "site=apt.llvm.org,component=main";
}