flatpak-builder builds killed by xdg-desktop-portal due to background restriction

[YaLTeR]

My flatpak-builder build was inexplicably getting SIGKILLed seemingly on a time-out. After hours of debugging, I found out that it was getting killed by xdg-desktop-portal. Turns out, the app-id of my manifest was somehow denied background operation (according to permission-viewer) so xdg-desktop-portal was killing bwrap spawned by bwrap spawned by flatpak-builder. I don't recall seeing any GNOME Shell prompt for background operation related to this app-id. Allowing the background operation for the app-id in permission-viewer fixed the issue.

Here's the manifest that I used. sleep 300 was more than enough to trigger the issue.

{
    "app-id" : "org.sourceruns.VideoTrimmer",
    "runtime" : "org.gnome.Platform",
    "runtime-version" : "3.36",
    "sdk" : "org.gnome.Sdk",
    "sdk-extensions" : [
        "org.freedesktop.Sdk.Extension.rust-stable"
    ],
    "command" : "video-trimmer",
    "finish-args" : [
        "--share=ipc",
        "--socket=fallback-x11",
        "--socket=wayland"
    ],
    "build-options" : {
        "append-path" : "/usr/lib/sdk/rust-stable/bin",
        "build-args" : [
            "--share=network"
        ],
        "env" : {
            "CARGO_HOME" : "/run/build/video-trimmer/cargo",
            "RUST_BACKTRACE" : "1",
            "RUST_LOG" : "video-trimmer=debug"
        }
    },
    "cleanup" : [
        "/include",
        "/lib/pkgconfig",
        "/man",
        "/share/doc",
        "/share/gtk-doc",
        "/share/man",
        "/share/pkgconfig",
        "*.la",
        "*.a"
    ],
    "modules" : [
        {
            "name": "ffmpeg",
            "buildsystem": "simple",
            "build-commands": [
                "sleep 300"
            ],
            "config-opts": [
                "--disable-doc",
                "--disable-decoders",
                "--disable-encoders",
                "--disable-devices",
                "--disable-ffplay",
                "--disable-ffprobe",
                "--enable-gpl"
            ],
            "cleanup": [
                "/include",
                "/lib",
                "/share"
            ],
            "sources": [
                {
                    "type": "archive",
                    "url": "https://www.ffmpeg.org/releases/ffmpeg-4.2.2.tar.xz",
                    "sha256": "cb754255ab0ee2ea5f66f8850e1bd6ad5cac1cd855d0a2f4990fb8c668b0d29c"
                }
            ]
        },
        {
            "name" : "video-trimmer",
            "builddir" : true,
            "buildsystem" : "meson",
            "sources" : [
                {
                    "type" : "dir",
                    "path" : "."
                }
            ]
        }
    ]
}

[YaLTeR]

As an update, I changed the app-id and did indeed get a Shell dialog asking me whether I want to allow or deny the background operation. According to @barthalion on #flatpak, builds should not be part of this.

[matthiasclasen]

Well, it is a feature to control background activity in flatpaks. If your builds are running in flatpaks, they are affected.

[barthalion]

This is relatively common problem though. Ideally there should be a way to exclude builds started by flatpak-builder from background activity control.

[gigitux]

Thanks for open this issue!

I also add an error log so that it can be found more easily:

Error: module youp: Child process exited with code 137

To reset the permission check the command:

flatpak permission-reset

[kparal]

I just spent several hours searching for some explanation for why my flatpak-builder exits at random points during compilation with

Error: module gtk2: Child process exited with code 137

and it was really hard to figure out, I found this ticket mostly by accident. Of course, I'm affected by the same issue. The app-id I was using had background operations disallowed, I have no idea why. flatpak permission-reset app-id resolved the problem.

Now, can we please make this more user friendly?

1. When a process is killed because background operation is disallowed, please print a message to system journal! This will make it much easier to find out what has happened.
2. It would also be good from users' POV to show a notification Flatpak app XYZ was terminated, because background operations were not allowed or similar.
3. Do the compilations need to run under the app-id, can't they run under the flatpak-builder ID? It seems really weird to combine these together. I might not want to allow background operations for a certain app, but I still want to be able to compile it...

At least 1) and 2) should be relatively easy to do, I hope, and would improve this situation dramatically. Thanks.

[sudopluto]

just ran into this issue, i agree that there needs to be a better heads up that this permission needs to be set.

[GeorgesStavracas]

Since #901 the background monitoring code is more lenient towards background-running apps, and won't kill them on spot, unless users actively disable that. That's enough to cover the use-case of GNOME Builder, although annoyingly, it shows up as a background app while compiling.

[matzipan]

Still a bit confusing. Came across this today while in GNOME.

While building I got the notification that the application is running in the background. I get the dialog with options "Force quit" and "Allow". At that time, I was still rebuilding so I did not expect my app to be running so I clicked "Force quit".

I spent the next hour debugging why my flatpak-builder space is getting killed at random times.

[j5155]

Would definitely agree that this is still confusing. 4 years later and I just spent the afternoon trying to debug why it was getting killed.