SUMMARY Error messages while launching the application as Appimage. OBSERVED Those commands allowed to launch the application: $ ./kdevelop Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway. kdevplatform.shell: Could not load plugin "KDevCMakeManager" , it reported the error: "Unable to find a CMake executable. Is one installed on the system?" Disabling the plugin now. kdevplatform.util: Path::init: invalid/unsupported Path encountered: http://clang-tidy kdevplatform.shell: Could not load plugin "KDevCMakeManager" , it reported the error: "Unable to find a CMake executable. Is one installed on the system?" Disabling the plugin now. Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString) kf5.kservice.services: The desktop entry file "/usr/share/applications/qemu.desktop" has Type= "Application" but no Exec line kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/qemu.desktop" kf5.kservice.services: The desktop entry file "/usr/share/applications/org.gnome.ChromeGnomeShell.desktop" has Type= "Application" but no Exec line kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/org.gnome.ChromeGnomeShell.desktop $ firejail --noprofile ./kdevelop Parent pid 24186, child pid 24187 Child process initialized in 7.18 ms Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway. kdevplatform.shell: Could not load plugin "KDevCMakeManager" , it reported the error: "Unable to find a CMake executable. Is one installed on the system?" Disabling the plugin now. kdevplatform.util: Path::init: invalid/unsupported Path encountered: http://clang-tidy kdevplatform.shell: Could not load plugin "KDevCMakeManager" , it reported the error: "Unable to find a CMake executable. Is one installed on the system?" Disabling the plugin now. Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString) kf5.kservice.services: The desktop entry file "/usr/share/applications/qemu.desktop" has Type= "Application" but no Exec line kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/qemu.desktop" kf5.kservice.services: The desktop entry file "/usr/share/applications/org.gnome.ChromeGnomeShell.desktop" has Type= "Application" but no Exec line kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/org.gnome.ChromeGnomeShell.desktop" Parent is shutting down, bye... Those firejail commands did not allow to launch the application: $ firejail ./kdevelop Reading profile /etc/firejail/default.profile Reading profile /etc/firejail/disable-common.inc Reading profile /etc/firejail/disable-passwdmgr.inc Reading profile /etc/firejail/disable-programs.inc ** Note: you can use --noprofile to disable default.profile ** Parent pid 24389, child pid 24390 Warning: cleaning all supplementary groups Child process initialized in 31.81 ms execv error: No such file or directory Parent is shutting down, bye... $ firejail --appimage ./kdevelop Mounting appimage type 2 Error mounting appimage: appimage.c:119 appimage_set: Invalid argument SOFTWARE/OS VERSIONS Appimage run on Linux Fedora 31, Wayland, Gnome. File renamed from "Kdevelop-5.5.0-x86_64.AppImage" to "kdevelop".
Sorry, I don't understand the report. Do all of those fail? I have no idea what firejail is, so I'm interested mostly in the first invocation. That does not display anything fatal in its output. Does that one not start KDevelop either? Might be related to Wayland, I don't know of anyone who tested the AppImage on Wayland so far.
Just name the element that would have been cause of your assumed non-understanding. Good to hear your affinity with Firejail. That last has a dedicated option covering the use of files as Appimages for a puepose. Not testing that application according to Best Practises is beyond my understanding. Time to close. I have to rely on programs properly tested regards security.