Boost AUR Compilation in Arch Linux with ccache

Introduction
#

Optimizing your Arch Linux experience goes beyond mere installation – it’s about maximizing efficiency during software compilation. In this guide, we’ll walk you through a powerful technique to dramatically reduce compilation times for AUR (Arch User Repository) packages using a tool called ccache.

Step 1: Install `ccache`
#

The first step towards speeding up your AUR package compilation process is installing ccache. This clever tool caches previously compiled object files and metadata, enabling faster subsequent compilations. To install ccache, use the following command:

sudo pacman -S ccache

Step 2: Customize `makepkg.conf`
#

Now, it’s time to tailor your makepkg.conf file to optimize your Arch Linux system. Follow these steps:

Open the makepkg.conf file using your preferred text editor. You can use a command like this to open it in the Nano text editor:
```
sudo nano /etc/makepkg.conf
```
Or you can choose any other text editor you’re comfortable with.
Inside the makepkg.conf file, you’ll find a section called BUILDENV. Locate the line that resembles the following:
```
BUILDENV=(distcc color ccache check !sign)
```
1. Remove the ! symbol in front of ccache, like this:
```
BUILDENV=(distcc color ccache check sign)
```

This adjustment enables the use of the ccache tool, which caches compilation output, thus speeding up subsequent builds.

Step 3: Identify Your CPU Cores
#

Before we fine-tune the MAKEFLAGS settings, let’s determine the exact number of CPU cores on your system. You can do this using either of the following methods:

Use the lscpu command:
```
lscpu
```
Alternatively, you can employ the nproc command for a quick overview of the available CPU cores:
```
nproc
```
Make a note of this number; we’ll use it in the next step to optimize compilation settings.

Step 4: Optimize `MAKEFLAGS` for Your CPU
#

With the core count known, adjust the MAKEFLAGS variable in the makepkg.conf file accordingly. Locate the section for MAKEFLAGS, either by scrolling or by using Ctrl+W and typing MAKEFLAGS. Modify the line to allow for parallel compilation. For example, if your system has 10 CPU cores, set it as follows:

#-- Make Flags: change this for DistCC/SMP systems
MAKEFLAGS="-j10"

Step 5: Add `ccache` to PATH
#

For seamless access to ccache commands, we’ll add the ccache binary directory to your system’s PATH. Open your shell’s configuration file using your favorite text editor:

For `bash` Users:
#

nano ~/.bashrc

For `zsh` Users:
#

nano ~/.zshrc

Add the following line to the bottom of the file:

export PATH="/usr/lib/ccache/bin/:$PATH"

Save the changes and exit the text editor.

Step 6: Refresh Configuration and Apply Changes
#

To apply the changes made to your shell’s configuration file, you need to refresh the shell’s configuration. This ensures that the new PATH settings for ccache are immediately available. Here’s how you can do it:

For `bash` Users:
#

source ~/.bashrc

The source command reads and executes commands from the specified file (in this case, ~/.bashrc), making the changes take effect in the current terminal session.

For `zsh` Users:
#

source ~/.zshrc

Similarly, source is used to execute the commands in ~/.zshrc, updating the configuration in your current terminal session.

By using the source command, you ensure that your shell recognizes the updated PATH and other configuration changes, allowing you to use ccache seamlessly without needing to open a new terminal window.

Step 7: Verify PATH Configuration
#

To ensure that the ccache directory has been added to your PATH successfully, you can check the PATH variable. Open a new terminal window to apply any recent changes and then enter the following command:

echo $PATH

If you see /usr/lib/ccache/bin/ included in the output, it confirms that the PATH configuration has been successfully applied.

Bonus Tip: Exploring Paths
#

If you’re curious about the different paths in your $PATH, you can use the echo command in combination with the tr command to list each path on a separate line. This can give you a clearer view of the directories included in your PATH. Run the following command:

echo $PATH | tr ':' '\n'

This will display a list of directories that are part of your $PATH. You can then scan through the list to see if the /usr/lib/ccache/bin/ directory is indeed included.

Conclusion
#

By incorporating ccache and optimizing your compilation settings, you’ve unlocked a new level of efficiency in your Arch Linux environment. The software installation process becomes remarkably faster, allowing you to focus on exploring and using the software you need without the wait.

Harness the power of ccache to supercharge your AUR package compilation, making your Arch Linux journey even more seamless and enjoyable.