When downloading an AppImage or an ELF binary (e.g. a .run file) and trying to run it from the Downloads drop-down, it shows this dialog box (Linux Mint here, but the dialog box is owned by the Firefox process): However, a .run or AppImage file is an application in itself. Usually, you'd chmod +x it and run the file itself. It doesn't make sense to use another program to run it when the file itself is runnable. There are many ways to fix this issue, including having a pre-set list of "usually runnable" file extensions or detecting ELF headers or shebangs and suggesting chmodding (with proper security notices) then running delegating the resposibility of launching the file to the distro/OS underneath, if it provides such mechanism. Unfortunately, xdg-open doesn't know about .run files for instance. [easiest] when clicking on the downloaded file, start the file manager with the downloaded file highlighted, and let the user continue from there What's for sure is that the above dialog box serves no purpose.
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