HowTo: contributing to app development with crossbuilder

[mymike]

Hi, today I finally had another try with crosscompile.
I got this in the setup https://paste.ubuntu.com/p/5KWj5j9HjQ/
and this trying to execute the rotation-lock indicator https://paste.ubuntu.com/p/hDntZ43mRy/

but what about merging this tool with clickable? it already creates working containers (with docker and not lxc) and I think it just need to add the code to build something that isn't a click package and to install it on the device. also you'll use a unique container ans save disk space. but idk, maybe it's just a silly suggestion...

[mymike]

Oh, wait. I re-run crossbuilder and it has now a long log https://paste.ubuntu.com/p/vSxrr4K7Gn/ and it is complaining about some deps for indicator-display but idk if it's crossbuilder fault or it's indicator's...

[matteo]

@mymike Michele, would you mind trying to create a container also with the keyboard package cloning it from here as I already did before? I have had several errors (see previous outputs from me) and I'd like to see what's different from your output. Thanks.

P.S. what's your Desktop OS? Mine is Ubuntu 16.04.

[Luksus]

Just want to add my findings in trying to use crossbuilder:
Ubuntu 17.04 (32bit)

setup-lxd without zfs went well.
When trying to build with "crossbuilder --ubuntu=16.04" it stops with this error:
https://paste.ubuntu.com/p/YzNbHgGPpJ/

[matteo]

@luksus Why is your output so short? Did you cut it up to the essential?
For the error which states 'no device' are you sure you connected your phone to your PC prior to send the crossbuilder command? A tip for you: once connected the device to your PC, you don't need to type the complete command but you just need to write 'crossbuilder' and the script will detect by itself the OS (16.04 or 15.04).

[matteo]

@mardy I think I made one step further. First I just realized that the -su: dch: command not found error is only thrown when I try to crossbuild again the keyboard package when it has been already created. If I wipe the container by lxc stop ubuntu-keyboard-usdk-16-04-amd64-armhf-dev and then lxc delete ubuntu-keyboard-usdk-16-04-amd64-armhf-dev and I crossbuild it at its location, therefore the Container is not connected to the Internet. error is generated.
Secondly, I dug into the crossbuilder script and I found that this error, for my case at least, is a fake error. In fact, if I type in the terminal lxc info ubuntu-keyboard-usdk-16-04-amd64-armhf-dev I got this output:

As you can see the connection is actually available for the container (eth0: inet6).
However, running the script it is not detected because there is a typo in the concerned code rows:

If I get rid of the \b in grep -e "eth0.*inet\b" then the connection is correctly detected and the setup can move forward.
Moving forward I got new errors in fetching some repositories. I'm not sure if the crossbuilt succeeded this time; trying to make a small change locally to the keyboard package and crossbuilding it on my phone, it seems I'm not able to see any difference...maybe it's me and probably I touched something not graphically evident as I thought. I'll make other attempts before to be sure I'm not able yet to make crossbuilder to properly work.
The very latest output, if you want to help me to understand if the repositories fetching error is problematic and how to circumvent this, is the following: https://paste.ubuntu.com/p/5w78Gz2MJx/.

[Luksus]

@matteo : No I did not cut that output. I did not connect my device, because I thought its not necessary and it would proceed building anyway.
I thought the error is, that it does not find the requested image container at https://sdk-images.ubports.com.

[mymike]

@luksus maybe there aren't 32bit images to create the container

[mymike]

@matteo that ipv6 address is a link-local one, that means it could be used only in local network so, of course, it couldn't reach the internet and fetch the repos...

[mymike]

@matteo I tried but I got some dependencies issues like I got for the indicator-display (of course the deps where different) I have ubuntu 18.04

[matteo]

@luksus thank you for the insight. But I don't understand which repositories are needed and which aren't...Do you and @mymike know something about that? Unfortunately I think we are alone in this...:(

[matteo]

@mymike I don't follow you: which ipv6 address error are you talking about regarding the dependencies? Please, give me more insight about it.

[mymike]

@matteo idk which repos are needed. once the container is running it may have to install updates or dependencies requested by the component you're building, but if no internet connection is found it couldn't download them...

[mymike]

@matteo well, you said a connection is available for your container (eth0: inet6) with the addres fe80::216:3eff:fef5:570c, but that address cannot pass through router, it can only be used inside your local network: it cannot access the internet, so it is normal that deps aren't downloaded as no internet connection is found

[matteo]

@mymike oooooh ok.....thank you for the tip. So, according to your comment I actually don't have internet connection, is that right? But how is so? Are we talking about internet connection on my PC right? I do have it...weird...

[mymike]

@matteo no, its the container that doesn't have internet connection.

As you also said here:

I got always the same error: "Container is not connected to the Internet."

containers I think doesn't connects directly to internet using your pc connection but create a bridge (if I understood it correctly), so the container connection pass through the bridge and then to your pc connection. but the bridge seems to be broken

[UniSuperBox]

I think I figured out a solution to the Container is not connected to the Internet error on Ubuntu 16.04.

It seems that LXD switched to setting up its default bridge lxdbr0 as link-local only (no Internet connection) around the beginning of April 2016: article explaining the change here. From what I can tell, this decision was reversed before the release of 18.04 because the issue does not occur there. I'll see if I can submit a patch to Crossbuilder to fix this.

Edit: This is no longer needed!

See this post below. A fix has been merged into Crossbuilder.

Fix "Container is not connected to the Internet"

To set up the bridge on your system, run sudo dpkg-reconfigure -p medium lxd. If you like you can carefully answer each question, but mashing enter to get through the setup works too. This will add an IPv4 and IPv6 subnet to your bridge.

After setting up the bridge, your crossbuilder container still won't be set up correctly. Delete it by running crossbuilder delete.

Once you complete these steps, you should be able to run crossbuilder successfully.

[matteo]

I first would like to thank @mymike for his clever intuition regarding the missing bridge and then @UniSuperBox for the hotfix found: it works (without the need to crossbuilder delete)! I'm able now to download the repositories and the installation goes further and further.....until to throw an ultimate error complaining about broken packages. Here it is the new complete logfile:

https://paste.ubuntu.com/p/NNGs9ChB63/

[mardy]

@matteo said in HowTo: contributing to app development with crossbuilder:

I'm able now to download the repositories and the installation goes further and further.....until to throw an ultimate error complaining about broken packages. Here it is the new complete logfile:

https://paste.ubuntu.com/p/NNGs9ChB63/

You need to edit the debian/control file of the project, and add a <!nocheck> next to xvfb, similarly to how it's done here. That's because this package is only used for running the tests, and tests are not run when using crossbuilder. You can do the same for the python packages.

After you manage to build the package with crossbuilder, it would be nice if you could create a pull request with your changes, so that the next contributor won't have to go through the same pain.

[matteo]

Thank you for your reply @mardy! I will try to follow your suggestions as soon as I'll have some additional spare time and report here the findings.
After, consider the PR done, no problem

Matteo