Build error with .desktop

snap
1

Error msg :
…
Priming desktop-stellarium
Priming stellarium
‘grade’ property not specified: defaulting to ‘stable’.
Failed to generate desktop file: Invalid desktop file ‘$SNAP/usr/share/applications/stellarium.desktop’: does not exist (defined in the app ‘stellarium’).
Build failed


.yaml entry : 
 ...

apps:
  stellarium:
    command: bin/desktop-launch $SNAP/usr/bin/stellarium-daily
    desktop: $SNAP/usr/share/applications/stellarium.desktop
    plugs: [desktop, wayland, x11, unity7, opengl, network, network-bind, audio-playback, home]

parts:

  stellarium:
    plugin: cmake
    source: https://github.com/Stellarium/stellarium.git
    source-type: git
    source-depth : 1
    after : [desktop-stellarium]
.....

NB : The location of the .desktop file is under /usr/share/applications/stellarium.desktop when installed through apt
2

Don’t prefix the path with $SNAP/:

apps:
  stelarium:
    desktop: usr/share/applications/stellarium.desktop
3 
Priming stellarium 
'grade' property not specified: defaulting to 'stable'.
Failed to generate desktop file: Invalid desktop file 'usr/share/applications/stellarium.desktop': does not exist (defined in the app 'stellarium').
Build failed
4

You need to copy the desktop file into your snap, one way or the other. See Desktop files for menu integration:

There are three methods to tell snapcraft which desktop entry files to use.

5

After detail reading of the error log it is found that location of .Desktop file is /share/… and /share lies outside the /usr folder. Hence used external metainfo and build-override. Snap doesn’t recognize .Desktop file and associated icons which lies outside of /usr

parse-info: [share/metainfo/stellarium.appdata.xml] #appstream info
after : [desktop-stellarium]
override-build: | #added to show app in launcher menu
  snapcraftctl build
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/applications
  cp ../src/data/stellarium.desktop $SNAPCRAFT_PART_INSTALL/usr/share/applications
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/16x16/apps
  cp ../src/data/icons/16x16/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/16x16/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/32x32/apps
  cp ../src/data/icons/32x32/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/32x32/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/48x48/apps
  cp ../src/data/icons/48x48/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/48x48/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/64x64/apps
  cp ../src/data/icons/64x64/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/64x64/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/128x128/apps
  cp ../src/data/icons/128x128/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/128x128/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/256x256/apps
  cp ../src/data/icons/256x256/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/256x256/apps
  mkdir -p $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/512x512/apps
  cp ../src/data/icons/512x512/stellarium.png $SNAPCRAFT_PART_INSTALL/usr/share/icons/hicolor/512x512/apps

Is there any way to force snap to use .desktop file outside /usr but inside /share/applications/ ?