Debian Buster

[schmidtbag]

So I'm working on this project with Python 3 + OpenCV on my U2. Currently, I'm trying to run this on Arch Linux, since it remains fully up-to-date. Unfortunately, there seems to be some build problem in Arch regarding gstreamer plugin (for all architectures, not just ARM). An older version is known to work, but the downgrader tool doesn't work on ARM. And since Arch is rolling release, I can't just use an old repo. So, rather than wait around for someone to figure this out, I'd rather just go with Debian Buster.

The tricky part is, the U2's Debian images are very outdated, and the Ubuntu packages seem to be even moreso. To my knowledge Debian Jessie is the newest release available to the U2, and that's 2 generations older than Buster. A lot has changed since then, so I'm worried if it's going to break.

Is anybody currently running Buster, or Sid on the U2 or U3?

[meveric]

To my knowledge Debian Jessie is the newest release available to the U2, and that's 2 generations older than Buster.

That's true, but Debian Buster is not released yet and won't be for another couple of years so it's the next testing version and nothing I would consider "stable".
Debian Jessie is still "old-stable" and widely supported.
Debian Stretch is the current stable release but requires Kernel 3.16 or higher which is one of he reasons it's currently not available for ODROID U2 as it officially only comes with Kernel 3.8.

A lot has changed since then, so I'm worried if it's going to break.

Debian Stretch already requires at least Kernel 3.16 I don't know what's the minimal requirement for Buster, but at least 3.16 as well, so it's likely a few things won't work.

Is anybody currently running Buster, or Sid on the U2 or U3?

Sid is permanent unstable/testing branch using this is very likely to cause issues, if you use "sid" as your "main" OS you're adventurous and expect to encounter issues and feel confident enough to solve them.
Same goes for Buster at the moment as it's "years" before it's going to be released, so everything is subject to change and an update can easily break something, even IF the Kernel was actually supported.

[schmidtbag]

Debian Stretch is the current stable release but requires Kernel 3.16 or higher which is one of he reasons it's currently not available for ODROID U2 as it officially only comes with Kernel 3.8.

This part here is what especially concerns me about attempting an upgrade. I understand the 3.8 kernel is necessary for the closed-source drivers, but this leads me to wonder the following:
1. Couldn't I still install Jessie and upgrade to the Stretch or Buster repos while retaining the old 3.8 kernel?
2. I actually don't need the closed-source drivers (I assume OpenCV won't take advantage of them?) so in the event I upgrade the kernel, would the system still boot properly if I were to upgrade the kernel?
Keep in mind, Arch is using I think the 4.17 kernel, so I know newer kernels do function on the U2 (but, I don't have the Mali drivers).

Debian Stretch already requires at least Kernel 3.16 I don't know what's the minimal requirement for Buster, but at least 3.16 as well, so it's likely a few things won't work.

I was wondering more specifically along the lines of things like systemd or other low-level functions that may have broken in between releases.

Sid is permanent unstable/testing branch using this is very likely to cause issues, if you use "sid" as your "main" OS you're adventurous and expect to encounter issues and feel confident enough to solve them.
Same goes for Buster at the moment as it's "years" before it's going to be released, so everything is subject to change and an update can easily break something, even IF the Kernel was actually supported.

To clarify, I'm not seeking to use sid. The purpose of my question was more to figure out if people have a known working system using significantly newer packages. In other words, if someone can get sid to work, I should be able to get buster to work. I only intend to install roughly 2GB worth of packages, so I'm willing to take any risk of breakages. Frankly, a repo with the potential to break is currently a better option for me than Arch, which is currently broken. So, I'm willing to take my chances.

[meveric]

1. Couldn't I still install Jessie and upgrade to the Stretch or Buster repos while retaining the old 3.8 kernel?

Doesn't matter if you install Stretch directly or if you update to Stretch. Stretch is Stretch and it requires Kernel 3.16 to work properly. It will start on Kernel 3.8 but some system calls are missing and you'll see error's all over the place.
Most of the programs you start will create a Kernel warning/error entry as they require syscalls that do not exist in Kernel 3.8.

2. I actually don't need the closed-source drivers (I assume OpenCV won't take advantage of them?)

As far as I know OpenCV is suppose to use GPU acceleration for deep learning. So it might require GPU after all. But should be able to run on CPU only as well.

so in the event I upgrade the kernel, would the system still boot properly if I were to upgrade the kernel?

There are some newer Kernel that support Mali GPU drivers on the U2 as well, using a newer Kernel would work, it's just that it's not officially available and you would have to build it yourself.
You can't just click on a button and it's installing a newer Kernel, there is much more work involved including updating the u-boot and other things.

I was wondering more specifically along the lines of things like systemd or other low-level functions that may have broken in between releases.

Unlikely that's kept stable between releases. Also even Debian Jessie already used systemd so there won't be any issue in that field. The Kernel is the issue, not the OS.

To clarify, I'm not seeking to use sid. The purpose of my question was more to figure out if people have a known working system using significantly newer packages. In other words, if someone can get sid to work, I should be able to get buster to work.

Buster and Sid are currently kinda the same, as Buster is the current testing release and is not released yet (and won't be for quite some time).
Also "newer packages" have not necessarily anything to do with the OS you're running on.
I'm using ffmpeg from Debian Buster on Debian Jessie, I simply backported and build it on Debian Jessie together with some packages from Debian Stretch that were requirements.
I did this to get hardware accelerated ffmpeg support for MFC encoder/decoder on the XU3/XU4 and Kernel 4.14.

[schmidtbag]

Doesn't matter if you install Stretch directly or if you update to Stretch. Stretch is Stretch and it requires Kernel 3.16 to work properly. It will start on Kernel 3.8 but some system calls are missing and you'll see error's all over the place.
Most of the programs you start will create a Kernel warning/error entry as they require syscalls that do not exist in Kernel 3.8.

Ah ok. I guess that settles it then - definitely won't use Buster (if I'm locked to the 3.8 kernel).

As far as I know OpenCV is suppose to use GPU acceleration for deep learning. So it might require GPU after all. But should be able to run on CPU only as well.

OpenCV does have GPU acceleration, but it's primarily in CUDA. There is some OpenCL acceleration but to my understanding, it's only for very specific uses.

There are some newer Kernel that support Mali GPU drivers on the U2 as well, using a newer Kernel would work, it's just that it's not officially available and you would have to build it yourself.
You can't just click on a button and it's installing a newer Kernel, there is much more work involved including updating the u-boot and other things.

I don't care enough about the GPU drivers to go through with that.

I'm using ffmpeg from Debian Buster on Debian Jessie, I simply backported and build it on Debian Jessie together with some packages from Debian Stretch that were requirements.

That might work fine for me - I wasn't aware you could backport that far ahead.

[meveric]

That might work fine for me - I wasn't aware you could backport that far ahead.

It won't work with every program, but you never know before you tried. I backported quite a lot of software already for Debian Jessie, long before Stretch became stable.

[schmidtbag]

Cool, good to know. Well thanks for the tips and the detailed descriptions - much appreciated.