Frequent questions

How do I..? hitchhiker’s Ops guide to the galaxy. This document tries to collect the frequent questions while operating the MocaccinoOS tree

This document has the objective to address several questions that starts with “How do I … ?”

How do I start contributing?

Have a look at the official Luet docs about package building, and feel free to submit your first PR! Be sure to also read all this document to get an Idea on how things should look like.

How do I know which version of a package is available in the Portage tree

We pin Portage versions by using packages that are shipping a version of it. This guarantees that there are no moving parts, and we can in this way provide updates as part of a development lifecycle.

We have an automated bot that automatically opens PR to track new version of the available Portage version. The package is available here: You don’t need to do it manually. Just wait for a PR from MarvinHatesOceans to pop-up, we will review it and merge it only when we decide (after proper QA) that a development lifecycle is over.

A Portage bump happens when:

  • We close a dev cycle (release, and upgrades)
  • Security fixes

So, how do I know which package I can build?

At the moment is as easy as browsing the portage git and point it at the same commit of our package.

For example:

git.hash: "b0e157b071cb23b348acab3d596b49f66c244808" in tells you that we are pinning at commit b0e157b071cb23b348acab3d596b49f66c244808 of portage tree. So you can e.g. point your browser at :

How do I revbump a package? (and when it’s actually needed?)

By convention, we have chosen to increment the version of a package after the +, following semver notation.

That means, if a package version is at 1.0.0, it’s revbump version would be 1.0.0+1, and a subsequent one would be for example 1.0.0+2.

When I do need to bump a package?

Only when there is a new version available!

When I do need to revbump a package?

A Package revbump is necessary when you apply changes to build.yaml, although, it’s not always necessary, but just in few cases:

  • When you change steps in the build.yaml
  • When you change prelude in the build.yaml
  • When you change requires in the build.yaml

What about packages depending on it?

Always by convention, we have chosen to revbump manually those. Luet does support tracking automatically new package versions, but we want to make this transparent in the Git repository, so reverting changes introduced by mistakes it’s easier, and so we also rely on the caching mechanism of Luet.

If we don’t revbump reverse dependencies our CI would skip such changes, because we enforced this by policy.

How do I do that?

Until is delivered, it is a manual process.

How do I add a useflag to a Portage package or layer?

If the useflag you are going to add doesn’t have an huge impact on its dependencies (not requiring a rebuild) then it’s fine to apply at the spec-level. Otherwise it might be required to specify the useflags needed in that specific package, or on the parent layer which your package is depending on, requiring a package revbump.

Take the layers/system-x package as an example, in the prelude steps of the package, we copy over the building container the custom useflags in the prelude steps:

- cp -rf package.use /etc/portage/
- cp -rf make.conf /etc/portage/
- cp -rf package.accept_keywords /etc/portage/
- cp -rf package.license /etc/portage/

the package.use folder is actually shipped with the package spec. That approach can be used also in layers depending on system-x, with a separate set of flags. You just have to be sure to not override any useflag between layers, and to try to share as much as you can with parent layers while do you see it fit.

How do I split a package?

A layer can be split into multiple packages, using the excludes/includes pattern which is used for example by gcc and gcc-base. This means you can safely compile packages into parent-layers, and exclude those in the final artifact which gets installed by the end-user.

For example, for gcc we drop the files from system-x, and we include explicitly files to the gcc package, which at that point doesn’t need to compile anything by itself. It just needs to depend on the parent layer, so all the gcc files are accessible from that container.

In the system-x spec, you will find something similar:


# GCC split
- ^/etc/env.d/04gcc-x86_64-pc-linux-gnu
- ^/etc/
- ^/etc/env.d/gcc.*
- ^/usr/lib/debug/usr/lib/gcc.*
- ^/usr/lib/gcc/x86_64-pc-linux-gnu.*
- ^/usr/share/gcc-data/x86_64-pc-linux-gnu.*
- ^/usr/bin/c\+\+.*
- ^/usr/bin/cc$
- ^/usr/bin/cpp.*

This tells luet to exclude those files from the final artifact.

Similarly, you can find in the gcc package those files being included:

- /usr/lib/gcc$
- /usr/lib/gcc/x86_64-pc-linux-gnu$
- /usr/lib/gcc/x86_64-pc-linux-gnu/{{.Values.version}}.*
- /usr/lib/go$
- /usr/lib/go/{{.Values.version}}.*
- /usr/lib64$
- /usr/lib64/go$
- /usr/lib64/go/{{.Values.version}}.*
- /usr/libexec$
- /usr/libexec/gcc$
- /usr/libexec/gcc/x86_64-pc-linux-gnu$
- /usr/libexec/gcc/x86_64-pc-linux-gnu/{{.Values.version}}.*
- /usr/share$
- /usr/share/gcc-data$
- /usr/share/gcc-data/x86_64-pc-linux-gnu$
- /usr/share/gcc-data/x86_64-pc-linux-gnu/{{.Values.version}}.*

How do I try my changes?

You need at least Docker running locally, or img installed.

To build a package, just edit/add the relevant specs and run PACKAGES=".." make rebuild-all.

How can I debug the build environment?

Luet generates docker images for each package, you can start a shell by either retrieving manually the docker image of the package with luet tree images and manually run docker run.. on it or you can use the luet extension which does that already for you. You need to have installed system/luet-devkit package, and you can use it as follows:

DOCKER_HOST="..." LUET_ARGS="--image-repository" luet remote-exec packagename

Note: It’s not required DOCKER_HOST unless you want to leverage a remote host.

Once you are hooked into the container there are some limited tools at your disposal that might help you. For instance if you want to list all the atoms that are installed you can do:

qlist -IRv

How do I add a package?

Have a look at the official docs about specfile and their syntax. After you familiarize with it, you can just open up a PR, by taking as an example an already existing layer. See, for example calamares

How do I update provides list, and what are they?

Provides are packages that your layer/package is going to satisfy. That means if other packages are depending on a package/foo, and that is provided by package/bar, package/bar will get installed in place of package/foo.

At the moment it’s a manual process - and we will work an automated way as soon as we have bandwidth for it. This mechanism it’s used to ensure a smooth migration path from Sabayon/Entropy based systems.

How do I know that a package belongs to a Layer?

Packages belonging to a layer should be listed as provides, and also part of the arguments to emerge for compiling that package. Until we deliver - it is also a manual process. Refer to the section of this document “How can I debug the build environment?” to see how to hook directly into a package container to inspect its content.

How do I find the duplicate files in the package repositories?

You can use luet search and luet filter to compose a list of duplicate files. luet 0.11.3 returns the files in the packages as part of the json result:

luet search -o json | luet filter

To install luet-filter, just run:

luet install -y extension/filter

Note: luet search searches into online repositories enabled in the system unless --installed is specified. You need to have the desktop repo enabled locally in order to retrieve this list.

Filter by package fields

As luet filter can be piped, you can use jq to narrow down the search by specific by package fields. For example, to filter out by category, you can:

$ luet search -o json | jq '{ packages: [.packages[] | select( .category == "kernel-modules" )] }' | luet filter
Duplicate found for etc/modprobe.d/vboxdrv.conf in kernel-modules/virtualbox-modules kernel-modules/virtualbox-modules-lts
Duplicate found for usr/lib/modules-load.d/virtualbox.conf in kernel-modules/virtualbox-modules kernel-modules/virtualbox-modules-lts

Note, the query is select( .category == "kernel-modules" ) and you can customize it further to narrow down to specific queries.


Filtering kernel

luet search -o json | jq '{ packages: [.packages[] | select( .category != "kernel" )] }' | luet filter >> dups.txt

Filtering ‘layers’ and ‘repository category

luet search -o json | jq '{ packages: [.packages[] | select( .category != "repository" ) | select(.category != "layers") ] }' | luet filter >> dups.txt

The package I want to add needs a user/group. Where do I add it?

The user/groups in MocaccinoOS are defined by entities. They are an uniform way to define user/groups across different distributions in a unique and interoperable way. The same users/groups are indeed shared with Mocaccino Micro.

All the users groups are defined in a unique collection inside the os-commons repository, here

How do I add a system-wide extension, or configure a gnome setting?

We have a gnome-skel package for that purpose. Check the content, apply the required changes and bump the package version.

Last modified August 3, 2021: Add more samples (dc6b5a0)