Go to apt.llvm.org to get the correct distro.
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:
$(wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sed 's/^/ /')
EOD
For older distributions not supporting .sources files.
The repository PGP key is already installed it seems for a desktop distribution.
When it is not use the following command to add the key.
wget https://apt.llvm.org/llvm-snapshot.gpg.key -O /etc/apt/trusted.gpg.d/apt.llvm.org.asc
echo "deb [arch=amd64] http://apt.llvm.org/$(lsb_release -sc)/ llvm-toolchain-$(lsb_release -sc) main" > /etc/apt/sources.list.d/llvm-toolchain.list
Since almost every day there is a new release of the LLVM packages unattended upgrades can be configured.
Command to install the needed package.
apt install unattended-upgrades
Enable it by using the following command.
dpkg-reconfigure -plow unattended-upgrades
It modifies /etc/apt/apt.conf.d/20auto-upgrades setting two flags as below.
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
Get some information on the repository containing LLVM run
apt policy
Te result wil contain the following section.
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
With this information create the file /etc/apt/apt.conf.d/51unattended-upgrades-llvm having the following content.
Unattended-Upgrade::Origins-Pattern {
"site=apt.llvm.org,component=main";
}