(snip)
-- Running input plugin: gstreamer -- 
ERROR: Could not find plugin: gstreamer 

--------

(snipped Gstreamer output:)

...
[gstreamer/stdout]
[gstreamer/stdout] -- Copying files into AppDir --
[gstreamer/stdout]
[gstreamer/stdout] -- Deploying files into AppDir root directory --
[gstreamer/stdout] WARNING: No desktop file specified, using first desktop file found: squashfs-root/usr/share/applications/MyApp.desktop
[gstreamer/stdout] Deploying files to AppDir root using desktop file: squashfs-root/usr/share/applications/MyApp.desktop
[gstreamer/stdout] Deploying desktop file to AppDir root: squashfs-root/usr/share/applications/MyApp.desktop
[gstreamer/stdout] Creating symlink for file squashfs-root/usr/share/applications/MyApp.desktop in/as squashfs-root
[gstreamer/stdout] ERROR: Could not find icon executable for Icon entry: MyApp

ERROR: Failed to run plugin: gstreamer (exit code: 1)

...
[gstreamer/stdout] Manually setting rpath for squashfs-root/usr/lib/gstreamer1.0/gstreamer-1.0/gst-completion-helper
[gstreamer/stdout] Manually setting rpath for squashfs-root/usr/lib/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner
[gstreamer/stdout] Manually setting rpath for squashfs-root/usr/lib/gstreamer1.0/gstreamer-1.0/gst-ptp-helper
[gstreamer/stdout] Installing AppRun hook

-- Deploying icons -- 
Deploying icon MyApp.png 
WARNING: Could not find copyright files for file MyApp.png using dpkg-query 

-- Deploying desktop files -- 
Deploying desktop file ./MyApp.desktop 

-- Copying files into AppDir -- 
Copying file ./MyApp.desktop to squashfs-root/usr/share/applications/MyApp.desktop 
Copying file MyApp.png to squashfs-root/usr/share/icons/hicolor/256x256/apps/MyApp.png 

-- Deploying files into AppDir root directory -- 
Deploying files to AppDir root using desktop file: squashfs-root/usr/share/applications/MyApp.desktop 
Deploying desktop file to AppDir root: squashfs-root/usr/share/applications/MyApp.desktop 
Creating symlink for file squashfs-root/usr/share/applications/MyApp.desktop in/as squashfs-root 
Deploying icon to AppDir root: squashfs-root/usr/share/icons/hicolor/256x256/apps/MyApp.png 
Creating symlink for file squashfs-root/usr/share/icons/hicolor/256x256/apps/MyApp.png in/as squashfs-root 
Deploying AppRun symlink for executable in AppDir root: squashfs-root/usr/bin/MyApp 
Creating symlink for file squashfs-root/usr/bin/MyApp in/as squashfs-root/AppRun