Build for arm64 on amd64

[kiminuo]

Related to bitcoin-core#345
Related to WalletWasabi/WalletWasabi#4051 (comment)

This PR just shows how to do a deterministic build for arm64 architecture. It's not finished, polished, etc. The hope is HWI's support for arm64 will improve a bit.

Setup

To set up your environment, install:

sudo apt install qemu-user-static 

Build for arm64

Use docker buildx to replicate deterministic build instructions for the arm64 build:

docker buildx build --no-cache --platform linux/arm64 -t hwi-builder -f contrib/build.Dockerfile .

# Note: build_wine.sh was removed.
docker run --platform linux/arm64 -it --rm --name hwi-builder -v $PWD:/opt/hwi  --workdir /opt/hwi hwi-builder /bin/bash -c "contrib/build_bin.sh && contrib/build_dist.sh"

i.e. the change is:

-docker build --no-cache -t hwi-builder -f contrib/build.Dockerfile .
-docker run -it --name hwi-builder -v $PWD:/opt/hwi --rm  --workdir /opt/hwi hwi-builder /bin/bash -c "contrib/build_bin.sh && contrib/build_dist.sh && contrib/build_wine.sh"
+docker buildx build --no-cache --platform linux/arm64 -t hwi-builder -f contrib/build.Dockerfile .
+docker run --platform linux/arm64 -it --rm --name hwi-builder -v $PWD:/opt/hwi  --workdir /opt/hwi hwi-builder /bin/bash -c "contrib/build_bin.sh"

Limitations

So far I had no luck with building hwi-qt because I get the following error

Installing dependencies from lock file

Package operations: 14 installs, 0 updates, 0 removals

  • Installing shiboken2 (5.15.2): Failed

  RuntimeError

  Unable to find installation candidates for shiboken2 (5.15.2)

  at ~/.pyenv/versions/3.9.7/lib/python3.9/site-packages/poetry/installation/chooser.py:72 in choose_for
       68│ 
       69│             links.append(link)
       70│ 
       71│         if not links:
    →  72│             raise RuntimeError(
       73│                 "Unable to find installation candidates for {}".format(package)
       74│             )
       75│ 
       76│         # Get the best link

during execution of poetry install -E qt

What about Cirrus CI and an ARM64 dockerfile...?

https://cirrus-ci.org/guide/docker-builder-vm/#dockerfile-as-a-ci-environment says

With Docker Builder there is no need to build and push custom containers so they can be used as an environment to run CI tasks in.
Cirrus CI can do it for you! Just declare a path to a Dockerfile with the dockerfile field for your container (arm_containers are not supported yet) declaration in your .cirrus.yml like this:

i.e. "arm_containers are not supported yet" is important!

=> Not possible at the moment, I believe.

[kiminuo]

cc @achow101

[achow101]

Interesting, I had not considered using qemu before. I was going to just do the builds on actual hardware.

What is the difference between docker buildx and normal docker build? Are you using it just to be able to start container for a different platform?

It's probably fine to not ship hwi-qt for arm builds, but it would be nice if that would work.

[kiminuo]

What is the difference between docker buildx and normal docker build?

As https://docs.docker.com/buildx/working-with-buildx/ says

Docker Buildx is a CLI plugin [..]. It provides the same user experience as docker build with many new features like creating scoped builder instances and building against multiple nodes concurrently.

It's basically a more powerful wrapper if I'm not mistaken.

Are you using it just to be able to start container for a different platform?

Yes, that's exactly the reason I use it.

It's probably fine to not ship hwi-qt for arm builds, but it would be nice if that would work.

So I would be happy to make it work though at the moment I don't have an idea how to fix it. Any idea how to fix it would be much appreciated. Anyway, I will try to spend a bit more time and I'll try to fix it but I have only limited time budget for this unfortunately and I don't know poetry, python and qt all that good.

[kiminuo]

Ok, so I believe it's simply because https://pypi.org/project/shiboken2/#files does not provide arm64 wheel.

[kiminuo]

https://doc.qt.io/qt-5/linux.html makes me think that linux/arm64 support is not officially supported. So that might be a plausible explanation why the python wheel for arm64 does not exist.

https://wiki.qt.io/Qt_for_Python seems to indicate the same thing.

[SomberNight]

Ok, so I believe it's simply because https://pypi.org/project/shiboken2/#files does not provide arm64 wheel.

Maybe try installing PySide2 (or PyQt5) with apt (in build.Dockerfile), instead of pip.
Debian has arm64 builds of these packages. See e.g. https://packages.debian.org/bullseye/python3-pyside2.qtgui

[kiminuo]

Ok, so I believe it's simply because https://pypi.org/project/shiboken2/#files does not provide arm64 wheel.

Maybe try installing PySide2 (or PyQt5) with apt (in build.Dockerfile), instead of pip. Debian has arm64 builds of these packages. See e.g. https://packages.debian.org/bullseye/python3-pyside2.qtgui

Yes, I have tried to do that but Debian Stretch does not have that package by default (it has some older version). Your link links Debian Bullseye version of Debian. If I'm mistaken feel free to correct me.

[kiminuo]

-> bitcoin-core#615