appimagetool - AppStreamData - launchable? Help!!

[kuiperzone]

I'm having difficulty with an AppStream metadata file. (I'll include my complete appdata.xml file below -- does it look right?)

If I DON'T put in the following line in appdata.xml:

<launchable type="desktop-id">net.example.AppId.desktop</launchable>

I get the following error: E: net.example.helloworld:~: desktop-app-launchable-missing

OK, so I put the above line into the file. But now I get the warning:

W: net.example.helloworld:~: desktop-file-not-found

Now, I've discovered I can make this warning go away by putting a copy of the .desktop file into usr/share/applications. But this feels wrong, as the project already has a copy of the desktop file in the AppDir root. Moreover, I'm not sure the relative paths in the .desktop file under usr/share/applications would be correct anyway?

How can I solve this error and warning?

---

net.example.AppId MIT MIT

  <name>Hello World</name>
  <summary>Test application only</summary>

  <description>
      <p>This is a longer description. There is a minimum length for this, otherwise the builder tool may
      give you a warning. Replace this with your own here. This is a test.</p>
  </description>

  <releases>
      <release version="1.0.0" date="2023-01-01">
          <description><p>This is the latest release.</p></description>
      </release>
  </releases>

  <launchable type="desktop-id">net.example.AppId.desktop</launchable>

  <developer_name>Your Name</developer_name>
  <url type="homepage">https://example.net/</url>

  <screenshots>
      <screenshot type="default">
          <image>https://via.placeholder.com/800x450.png/0000FF/808080?text=Screenshot+(TBD)</image>
      </screenshot>
  </screenshots>

  <provides>
	  <id>net.example.AppId.desktop</id>
  </provides>

[probonopd]

Yes, the whole AppStream format can be a bit overwhelming, is complex, and is a moving target, making it hard to produce a correct one. Can you generate a working AppStream file using https://docs.appimage.org/packaging-guide/optional/appstream.html#using-the-appstream-generator?

(What happens if you use helloworld.desktop as the name of your desktop file in the AppDir, and as the value of <launchable> and <id>?)

[kuiperzone]

Hey - thanks for the reply.

Using the generator, you get the same thing as I included above regarding "launchable". I've just created one, which I'll paste below.

Yes, AppStream data appears an impossible moving target. It didn't used to generate these errors and warnings, and I'm wondering whether the validation tool is using online rules that are always changing.

  <?xml version="1.0" encoding="UTF-8"?>
  <component type="desktop-application">
      <id>net.example.helloworld</id>
      <metadata_license>MIT</metadata_license>
      <project_license>MIT</project_license>
      <name>HelloWorld</name>
      <summary>Test application</summary>
      <description>
	      <p>This is a longer description. There is a minimum length for this, otherwise the builder tool may give you a warning. Replace this with your own here. This is a test.</p>
      </description>
      <launchable type="desktop-id">net.example.helloworld.desktop</launchable>
      <url type="homepage">https://example.net</url>
      <screenshots>
	      <screenshot type="default">
		      <image>https://via.placeholder.com/800x450.png/0000FF/808080?text=Screenshot+(TBD)</image>
	      </screenshot>
      </screenshots>
      <provides>
	      <id>net.example.helloworld.desktop</id>
      </provides>
  </component>

[probonopd]

What happens if you

• Use helloworld.desktop instead of net.example.helloworld.desktop
• Have corresponding helloworld.desktop file(s) in your AppDir

We are not using online rules. But from time to time people are urging us to use newer versions of the validation tool, because the format is ever-changing. Argh.

[kuiperzone]

I think saving desktop as myapp.desktop rather than reverse DNS form solves the problem. Thanks.