# Another AUR Helper (incomplete) AUR is the Arch User Repository, where anyone can upload a PKGBUILD and supplementary sources to allow others to build their own packages for use in the Arch Linux distribution. I made an incomplete AUR Helper in Python, and decided to put it in a public repository. It's messy, and it requires a significant amount of set-up, but it works for me. It always builds in a CHROOT, and it lets the user check the PKGBUILD (by default) prior to building. There is no automatic dependency management. That must be done in the config. An example config is provided. Note that if a "install=\" is specified in the PKGBUILD, then the configured editor will also open the specified file once the PKGBUILD is approved by the user. This check is necessary because such "install scripts" define hooks that are run when the package is installed. # Things to know before using the helper ## Security Apparently `makechrootpkg` (provided by `devtools` pkg and used by this script) sources PKGBUILD files directly, meaning that if a malicious PKGBUILD is attempted to be built, it may cause an RCE kind of exploit with the current user. Thus, it is recommended to run this script in a container (like Docker or LXC) so that even if a malicious PKGBUILD is sourced, it will only affect the container. Though if you do set up a container, you may have to set up a directory mount to access the built packages. ## Soft-lock due to multiple possible dependencies Sometimes if a package prompts a user to select between alternate package dependencies, makechrootpkg will fail to select one by default (it will constantly output "y" to stdin when a selection requires an integer). This means you will need to check the logs as it is building a package to make sure this kind of soft-lock doesn't happen. Use `tail -f LOG_FILE` for example. If such a soft-lock happens, Ctrl-C the helper, and explicitly set a dependency in the TOML config file in a "other\_deps" array for the package like so: [[entry]] name = "sway-git" aur_deps = [ "wlroots-git", "swaybg-git" ] other_deps = [ "mesa" ] ## Package stdout/stderr size limit The possible issue of output logs filling up disk space is addressed with a "log\_limit" config option. By default, if the output log file reaches the limit, the compilation output is no longer logged to file in the logs dir. Change "log\_limit" in the config to a value in bytes if the default of 1 GiB is too little for your use case (if the size of your output logs extend past 1 GiB somehow). ### Error when reaching limit "error\_on\_limit" can be set to true/false in the config. If set to true, then the build will fail if the limit is reached. If set to false, then the build will continue even if the limit is reached. ## Soft-lock if `sccache` is preinstalled in chroot Apparently, some packages automatically use ccache/sccache if it is installed in the chroot, and in some cases, causes a soft-lock during a build. It is recommended to not have ccache/sccache preinstalled in the chroot and to just let the aur-helper-script install it when necessary. For example, when building `tenacity-git` with sccache preinstalled, the build will hang after the final build step. Apparently, killing the running `sccache` process stops the soft-lock in this case. ## Preloading ccache/sccache This script expects ccache and sccache not to be installed in the chroot (for reasons as mentioned in the previous section) and ccache or sccache will be appended to a pkg's "other_deps" if a ccache or sccache directory is configured for it. # Setting up the AUR Helper The AUR Helper requires several things: - A CHROOT to build in. - A "checking GNUPG" directory that contains the GPG public keys that will be checked when building the PKGBUILD. - A "signing GNUPG" directory that contains the GPG private key that will sign the built packages and repository database. - SUDO privileges to be able to use `makechrootpkg`. - `/etc/pacman.conf` must be configured to use the custom repository's packages if `pacman -U ` will not be used. ## Dependencies The `devtools` package is required. The `python-toml` package is required for the Python script to run. ## Create the CHROOT Use `/usr/bin/mkarchroot` to create your CHROOT in a directory. mkarchroot $HOME/mychroot/root base base-devel cmake ninja As noted earlier, it is better to NOT preinstall `ccache` and `sccache`. You must refer to the CHROOT as `$HOME/mychroot` if you used the same name as in the previous example: mkarchroot $HOME/mychroot/root base base-devel cmake ninja BUILDCHROOT=$HOME/mychoot ## Set up the GNUPG dirs ### Checking GNUPG Just create the directory anywhere, and store it in the `config.toml`. You must manually add public keys to it if a package requires checking source files with GNUPG. GNUPGHOME=$HOME/myCheckingGNUPGDir gpg --recv-keys A_DEV_KEYS_FINGERPRINT Note that gpg may not automatically create the GNUPGHOME directory. ### Signing GNUPG You will need to set up a GPG public/private key pair. GNUPG always respects the `GNUPGHOME` environment variable as the `.gnupg` dir, so set the variable first, create the directory, then set up your keys. The keys will be used to sign the packages you build and the custom repository that stores the package metadata. Set the `signing_gpg_key_fp` variable in the config to the output fingerprint from of: GNUPGHOME=mySigningGNUPGDir gpg --fingerprint Note that you must remove the spaces between each part of the fingerprint, like in the example config. Keep note of the password you store for this GNUPG key, as you will enter it every time you use the Python script. ## Set up the config dir See the `example_config.toml` for more configuration. It should be commented enough for figuring out how to use it. ########## MANDATORY VARIABLES # If you did `mkarchchroot /home/username/mychroot/root base ...`, then the following must be: chroot = "/home/username/mychroot" # Location to place built packages. pkg_out_dir = "/home/username/pkgs" # It is recommended to put the repo file in the "pkg_out_dir". # If the tar file doesn't already exist, it will be automatically created. repo = "/home/username/pkgs/custom.db.tar" # Location to clone packages from AUR. clones_dir = "/home/username/aur" # add keys to checking GPG with: # `GNUPGHOME=/home/username/checkingGPG gpg --recv-keys ` gpg_dir = "/home/username/checkingGPG" logs_dir = "/home/username/aur/logs" signing_gpg_dir = "/home/username/signingGPG" # You can find the signing key's fingerprint with `gpg -k`. # Make sure it lists '[S]' before the fingerprint, as that means that key is a signing key. # You may have to use `gpg -k --with-subkey-fingerprint` if your signing key is a subkey. # Make sure the `signing_gpg_dir` is used: # `GNUPGHOME=/home/username/signingGPG gpg -k` signing_gpg_key_fp = "04D9E3A2880F6418EC4BA70EA0F3F8FAA2088E62" # It may be more helpful to set this to nano: # editor = "/usr/bin/nano" editor = "/usr/bin/vim" # if true, all logs are prepended with current time in UTC is_timed = true # if true, all output build logs are prepended with current time in UTC is_log_timed = true # Default log_limit is 1 GiB log_limit = 1073741824 # If true, then make the build fail if the limit is reached error_on_limit = false # If true, timestamps are in localtime. If false, timestamps are UTC. datetime_in_local_time = true # If true, all builds will be done in a tmpfs. Recommended to have a lot of RAM and/or swap. tmpfs = false ########## END OF MANDATORY VARIABLES ... [[entry]] name = "cpufetch-git" skip_branch_up_to_date = false aur_deps = [] other_deps = [] #ccache_dir = "/home/username/ccache_dirs/cpufetch_ccache" #sccache_dir = "/home/username/sccache_dirs/cpufetch_sccache" link_cargo_registry = false #repo_path = "https://example.com/mypkgrepo.git" #pkg_name = "cpufetch-git" ... # Setting up the Repository Create a directory for where you will store built packages and the repository. The name of the repo must be similar to the `repo` specified in the config. For example, if your repo's name is `MyAURRepo`, then `repo` should be set to `.../MyAURRepo.db.tar`. You must also create symlinks such that `MyAURRepo.db` points to `MyAURRepo.db.tar` and `MyAURRepo.files` points to `MyAURRepo.files.tar`. The Python script should automatically make a relative (not absolute) symlink to `MyAURRepo.db.tar.sig` with the name `MyAURRepo.db.sig` after signing (which should happen after each package is built and signed). Note the name doesn't have to be `MyAURRepo`, but is based on the `repo` variable set in the config. To use the repository, you can add an entry to your `/etc/pacman.conf` with the following: [MyAURRepo] SigLevel = Required TrustedOnly Server = file:///home/MyAURRepoDirectory # Optionally set a file with `Server = ...` entries # Include = /etc/pacman.d/my_repo_server_list Note that `SigLevel` is set expecting the `MyAURRepo.db` file to be signed (the Python script usually signs the `.db` file after a package has been successfully built). # Making your system trust the new Repository Export the public key from your `signingGPGDirectory`. GNUPGHOME=mySigningGNUPGDir gpg --export MySigningKeyName > $HOME/MySigningKey.pub Use `pacman-key` to add and trust it. sudo pacman-key -a $HOME/MySigningKey.pub First check that the name is unique: sudo pacman-key --finger MySigningKeyName Then trust it: sudo pacman-key --lsign-key MySigningKeyName After these steps, `pacman` should now trust the packages and repository signed by the GPG key you set up. # Using the AUR Helper Typically, you will invoke: ./update.py --config my_config.toml If you want to build in the CHROOT without updating the CHROOT, add the `--no-update` flag. If you want to check only specific packages in the list of packages in the config use something like `-p `. You can use `-p ` multiple times if you want to check a handful of packages only. If you want to not skip a package marked with `skip_branch_up_to_date` in the config, then use `--no-skip `, and the script will act as if `skip_branch_up_to_date` was not specified for the named package. When building, the script will not directly output to the terminal it is run in, but rather appends to log files in the log directory specified in the config. To see the output while building, you can use something like: tail -f $MY_LOG_DIR/google-chrome_stdout_2022-06-02_05-27-49_UTC It may be helpful to periodically clear out the logs directory in between invocations of the AUR Helper script. It is recommended to use the script with a prepared config. # Other Notes ~~By default, `makechrootpkg` does not verify integrity of files in the PKGBUILD. Use the `makechrootpkg_noskipinteg.hook` to modify the `makechrootpkg` script to not skip integrity checks.~~ `update.py` now does integrity checks before building with `makechrootpkg`. It is no longer necessary to modify the `/usr/bin/makechrootpkg` because the integrity checks are done separately. If the hook was used previously, remove it from `/etc/pacman.d/hooks` and reinstall `devtools`. ## `link_cargo_registry` If you have `.cargo/registry` and `.cargo/git` in your home directory, and you don't want to re-download the Rust registry every time you update a Rust package, you can specify `link_cargo_registry = true` for a package in your config (see `ion-git` in the `example_config.toml`) and that will bind-mount these two directories into the chroot, which will share your local Rust cache with the chroot. [[entry]] name = "ion-git" link_cargo_registry = true ## `is_timed` and `is_log_timed` If `is_timed` is `true` in the config, then output logs are prepended with a timestamp. If `is_log_timed` is `true` in the config, then output build logs are prepended with a timestamp. ## sccache and Rust If using `sccache` causes a build error when building a package compiling Rust, one may specify in the config to only wrap `rustc` and nothing else by specifying `sccache_rust_only`: [[entry]] name = "helix-git" link_cargo_registry = true sccache_dir="/home/user/aur/sccache_helix-git" sccache_rust_only = true ## Signal Handling The script is set up to handle `SIGINT` and `SIGUSR1`. `SIGINT` (Ctrl-C) will print the known package list and status, and exit. `SIGUSR1` will also print the known package list and status, but will not stop the script.