https://github.com/ryanprior/guadec-2020-guix-gtk
Files supporting my 2020 GUADEC talk, "Packaging GTK Apps in Guix"
https://github.com/ryanprior/guadec-2020-guix-gtk
Last synced: 4 days ago
JSON representation
Files supporting my 2020 GUADEC talk, "Packaging GTK Apps in Guix"
- Host: GitHub
- URL: https://github.com/ryanprior/guadec-2020-guix-gtk
- Owner: ryanprior
- Created: 2020-07-26T02:20:29.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2020-07-26T18:36:16.000Z (almost 5 years ago)
- Last Synced: 2025-05-07T23:03:36.588Z (11 days ago)
- Language: Scheme
- Size: 8.79 KB
- Stars: 2
- Watchers: 0
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.org
Awesome Lists containing this project
README
#+TITLE: Packaging GTK Apps in Guix
Your facilitator is Ryan Prior:
- Guix maintainer
- elementary OS community contributor
- https://www.ryanprior.com
* Workshop Overview
This is a technical workshop. As a participant you will have the opportunity to:
- use Guix to build software
- use Guix to create runtime environments
- read & write code
* Prerequisites
If you want to follow along, you should install these tools:
- a terminal emulator (like GNOME Terminal or Emacs)
- a text editor (like Geany or Emacs)
- ~git~
- GNU Guix 1.1.0 Binary (https://guix.gnu.org/download)
Then clone the repositories for Guix and this talk:
#+BEGIN_EXAMPLE
$ git clone https://git.savannah.gnu.org/git/guix.git
$ git clone -b start https://github.com/ryanprior/guadec-2020-guix-gtk.git
#+END_EXAMPLE
If you want to see the end result instead of following along step-by-step, omit
~-b start~ when you checkout the talk repo.
* Why Guix?
We want a computing experience that's carefree:
- Reliable, predictable behavior
- Reproducible across space, time
- Composable & flexible
- Safe for experimentation
* Guix delivers
Carefree computing:
- Pure environments for reliability
- Isolation and time-travel for reproducibility
- Seamless, accessible composition and flexible scripting
- Experimentation without side-effects, or with roll-back
* Testimonial
#+BEGIN_QUOTE
I still pity myself for having hesitated for so long to just dive into guix.
Made my hacking carefree. —André Batista (madage)
#+END_QUOTE
* Where does Guix fit?
Is Guix trying to replace Flatpak or Docker? -no.
Let's review how Guix works and how it compares to those complimentary
technologies.
* Overview of how Guix works
- Guix builds packages from source
- Users build from source or download binaries from a trusted substitute
- Builds are isolated and pure
- Runtime environment can be pure or impure
- Containers are optional (user's preference)
- Changes the environment by modifying ~PATH~ and similar variables
* Guix and Flatpak
Flatpak has end-user focus: tools and apps, not libraries or services. Guix
packages can be tools and apps, but can also be libraries, services, or data.
Composition of Flatpaks is mostly via D-Bus, while Guix packages can compose
seamlessly.
* Guix and Docker
Docker is focused on tools and services, not apps or libraries. Guix can output
container images compatible with Docker, so you can define a service in Guix and
deploy it anywhere.
Composition of Docker containers is mostly via HTTP, while Guix packages can
compose seamlessly.
* More about composition
In general you can't take two Flatpaks, or two Docker containers, and just merge
them. They aren't designed to be mutually compatible that way.
Guix packages are designed to be compatible that way.
You can:
- compose packages that use different, mutually incompatible versions of dependencies
- compose Guix packages with ~deb~, ~rpm~, ~apk~ packages
- use Guix packages on systems that don't have Guix installed
* Parts of a Guix package
A Guix package decription consists of:
- An exhaustive set of inputs
- A set of functions to transform the inputs into the outputs
- Data like title, version, description, and license information
Inputs are stored with hashes to avoid using an input that's been accidentally
(or maliciously) altered.
* What a Guix package looks like
(Paren warning: a package is defined using Guile scheme.)
Here's an example:
#+BEGIN_SRC scheme
(define-public gnome-menus
(package
(name "gnome-menus")
(version "3.32.0")
;; [snip—we'll revisit this soon]
))
#+END_SRC
* Where to find Guix package definitions
All the packages in upstream Guix—14k and counting!—are stored in the Guix source
code repository.
Clone it: ~git clone https://git.savannah.gnu.org/git/guix.git~
Browse to ~guix/gnu/packages~ and observe the many ~.scm~ files. These contain
package definitions.
Some especially relevant ones:
- ~gnome.scm~ :: GNOME software
- ~gnome-xyz.scm~ :: packages relevant to GNOME users but not part of GNOME
- ~pantheon.scm~ :: Pantheon desktop environment
- ~freedesktop.scm~ :: freedesktop.org software
* Let's look at some Guix packages
We'll look at 3 packages to gain some familiarity:
- ~gnome-menus~, a snack-size library package to get us started
- Seahorse, a handy GTK application; part of GNOME
- Sideload, a Pantheon (GTK/Granite) package; part of elementary OS
* gnome-menus
- a library package for libgnome-menu
- uses "GNU build system" which means ~configure~, ~make~, ~make check~, ~make install~
- few dependencies
Things you can do:
| view package definition | ~guix edit gnome-menus~ |
| build | ~guix build gnome-menus~ |
| install for your user | ~guix install gnome-menus~ |
| see info without installing | ~guix show gnome-menus~ |
* Seahorse
- a GNOME (GTK) application for handling keys and passwords
- uses "Meson build system"
- more dependencies
- some modifications to the build process
Things you can do:
| view package definition | ~guix edit seahorse~ |
| build | ~guix build seahorse~ |
| install for your user | ~guix install seahorse~ |
| run without installing | ~guix environment --ad-hoc seahorse -- seahorse~ |
* Sideload
- a Granite (GTK) application from elementary OS
- uses "Meson build system" again
- depends on Flatpak
- uses custom configure flags in build system
Things you can do:
| view package definition | ~guix edit sideload~ |
| build | ~guix build sideload~ |
| install for your user | ~guix install sideload~ |
| check if Guix has latest version | ~guix refresh sideload~ |
* Let's create a Guix package
Now that we're more familiar with Guix packages, let's create one.
We're going to package Planner, a GTK/Granite application that's part of the
elementary AppCenter.
* Planner
- a Granite (GTK) application from the elementary AppCenter
- link: https://planner-todo.web.app/
- created by Alain M., who gave me permission to use it as an example
Let's get started!
1. copy from a similar app (pantheon-calculator)
2. change the package name to planner
3. try to build: ~guix build -L. planner~
* package: unbound variable
#+BEGIN_EXAMPLE
ryan@swallowtail:~/dev/workshop/guadec-2020-guix-gtk$ guix build -L. planner
error: package: unbound variable
hint: Did you forget `(use-modules (guix packages))'?
guix build: error: planner: unknown package
#+END_EXAMPLE
4. copy module header from pantheon.scm
5. build again: ~guix build -L. planner~
* failed to load '(planner)'
#+BEGIN_EXAMPLE
ryan@swallowtail:~/dev/workshop/guadec-2020-guix-gtk$ guix build -L. planner
guix build: warning: failed to load '(planner)':
no code for module (planner)
./planner.scm:1:0: warning: module name (gnu packages pantheon) does not match file name 'planner.scm'
hint: File `./planner.scm' should probably start with:
(define-module (planner))
ice-9/eval.scm:223:20: In procedure proc:
error: granite: unbound variable
hint: Did you forget a `use-modules' form?
#+END_EXAMPLE
6. change ~gnu packages pantheon~ to "planner"
7. use the ~gnu packages pantheon~ module
8. build again: ~guix build -L. planner~
* successfully built
Finally, a success! Now on to the next target: actually building Planner.
#+BEGIN_EXAMPLE
successfully built /gnu/store/2n3vncz07bmsrjk1mlmzag96s3r94f7v-planner-1.5.5.drv
/gnu/store/nq3zrzp3q9alpq3p4lchvabg3kl7dl7g-planner-1.5.5
#+END_EXAMPLE
9. change the git URL to Planner's: https://github.com/alainm23/planner.git
10. change the version to the latest Planner release: ~2.4.6~
11. build again: ~guix build -L. planner~
* hash mismatch
#+BEGIN_EXAMPLE
r:sha256 hash mismatch for /gnu/store/g92sdba0gg14ginrlbypz9b439209xjz-planner-2.4.6-checkout:
expected hash: 1csxsr2c8qvl97xz9ahwn91z095nzgr0i1mbcb1spljll2sr9lkj
actual hash: 0z0997yq809wbsk3w21xv4fcrgqcb958qdlksf4rhzhfnwbiii6y
hash mismatch for store item '/gnu/store/g92sdba0gg14ginrlbypz9b439209xjz-planner-2.4.6-checkout'
build of /gnu/store/nfhpr64dmw3v1wljv3sxjfmf2jx8ycl6-planner-2.4.6-checkout.drv failed
#+END_EXAMPLE
We could just trust the "actual hash" but let's be skeptical:
12. clone [email protected]~ in a temporary directory: \\
~git clone --depth 1 -b 2.4.6 https://github.com/alainm23/planner.git /tmp/planner~
13. ask Guix for the hash of the resulting directory: \\
~guix hash -rx /tmp/planner~
#+BEGIN_EXAMPLE
ryan@swallowtail:~/moth.link/Documents/talks$ guix hash -rx /tmp/planner/
0z0997yq809wbsk3w21xv4fcrgqcb958qdlksf4rhzhfnwbiii6y
#+END_EXAMPLE
14. put the hash into our package definition
15. build again: ~guix build -L. planner~
* libecal
#+BEGIN_EXAMPLE
Run-time dependency libecal-2.0 found: NO (tried pkgconfig and cmake)
#+END_EXAMPLE
16. find the libecal package: ~guix package -A libecal~ \\
returns no results!
17. research libecal: it's part of Evolution
18. find the evolution package: ~guix package -A evolution~ \\
#+BEGIN_EXAMPLE
$ guix package -A evolution
evolution 3.34.2 out gnu/packages/gnome.scm:9583:2
evolution-data-server 3.34.2 out gnu/packages/gnome.scm:6369:2
#+END_EXAMPLE
19. add ~evolution-data-server~ to our inputs
20. build again: ~guix build -L. planner~
* json-glib
#+BEGIN_EXAMPLE
Run-time dependency json-glib-1.0 found: NO (tried pkgconfig and cmake)
#+END_EXAMPLE
21. find json-glib package: ~guix package -A json-glib~ \\
#+BEGIN_EXAMPLE
$ guix package -A json-glib
json-glib 1.4.4 out gnu/packages/gnome.scm:3522:2
#+END_EXAMPLE
22. add ~json-glib~ to our inputs
23. build again: ~guix build -L. planner~
* more inputs
We can follow the same workflow to find more, and we can also read ~meson.build~
for information about dependencies.
24. add more inputs:
- libical
- libsoup
- webkitgtk
25. use ~gnu packages calendar~ and ~gnu packages webkit~ modules
26. build again: ~guix build -L. planner~
* successfully built
#+BEGIN_EXAMPLE
successfully built /gnu/store/gjh5jgnhak94r5az7nczhsjpyn5a84sx-planner-2.4.6.drv
/gnu/store/b65v8bxpafs5i8adzypyqcrbnr2c86h5-planner-2.4.6
#+END_EXAMPLE
It builds now! [jazz music gets louder]
27. run planner:
~guix environment -L. --pure planner --ad-hoc planner -- com.github.alainm23.planner~
* org.gnome.desktop.interface
#+BEGIN_EXAMPLE
$ guix environment -L. --pure planner --ad-hoc planner -- com.github.alainm23.planner
(process:17238): GLib-GIO-ERROR **: 20:38:49.543: Settings schema 'org.gnome.desktop.interface' is not installed
#+END_EXAMPLE
[jazz music stops]
We soon discover that just because it builds doesn't mean it's packaged correctly.
28. research org.gnome.desktop.interface, discover it's part of ~gsettings-desktop-schemas~
29. add ~gsettings-desktop-schemas~ as an input and run again: \\
~guix environment -L. --pure planner --ad-hoc planner -- com.github.alainm23.planner~
(note: no need for an explicit rebuild, Guix will do that for us)
* missing the theme
Planner now runs! But… it doesn't look right. Icons are missing and colors are
off. It turns out that Planner, being an app designed for elementary OS, assumes
it's running on an elementary-like system with the right GTK theme and icon
theme installed.
Those themes aren't part of upstream Guix yet, but I happen to have packages for
them that I've been testing.
30. Copy Ryan's testing packages for ~pantheon-gtk-theme~ and
~pantheon-icon-theme~ from
https://github.com/ryanprior/guix-packages/blob/master/testing/pantheon.scm
31. add those as inputs & use the `xorg` and `inkscape` modules
32. run planner again
* Success!
Now Planner runs *and* renders correctly!
Next steps left as exercise for participants:
- update the rest of the package data
- investigate whether some inputs are unneeded at runtime (or at all)
- move those inputs to ~native-inputs~ (or remove them)
- lint your package (~guix help lint~)
- create a repo for your Guix packages & publish it there
- join the #guix channel on Freenode
- follow my social media (linked on my website)
- create another package!
Links:
- Your facilitator :: https://www.ryanprior.com
- This talk :: https://github.com/ryanprior/guadec-2020-guix-gtk
- Guix :: https://guix.gnu.org/