They might have it locked down for extra security, or the server might just be misconfigured. Normally for tight security you'd expect to see PHP commands like shell_exec() disabled. If phpThumb finds it can't exec anything it falls back to GD. But in your case it can run shell commands. It's able to do
which convert and find convert in /usr/bin. So it thinks "Ok, ImageMagick is installed. We'll use that." But when it actually tries to run convert it fails with some error ("whoami: cannot find name for user ID 1021081"). That's the source of the problem.
Since support says ImageMagick is not installed (it is), I'd put my money on the server not being configured quite right. If you have ssh access you could check it out a little more fully. If you can't run
convert from the shell, phpThumb is going to have problems.
Which PHP handler is this server using? If it's not FastCGI then the problem could be with the user PHP is run as. It's possible you could log in and run convert, but trying to call it from PHP fails because PHP is running as a different user.
[ed. note: jgrant last edited this post 10 years ago.]
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