command-line tool crashing

I use the DropDMG command-line tool extensively in automated build scripts. The last time I successfully ran one of these scripts was a couple months ago using DropDMG 3.5.5. Today I went to run one and was prompted to updated DropDMG and the command-line tool to 3.5.6, which I did. Now, attempting to run the command-line tool immediately fails like so:

$ dropdmg
Killed: 9

I’m running macOS 10.14.5 and have Xcode 10.2.1 installed if that matters. What’s going on? I need the command-line tool to work…

I’ve seen this a few times, and it seems to be a macOS issue that’s fixed by rebooting.

I did reboot before posting here and it didn’t help…tried it again after your suggestion, still no luck. Then I shut the machine down completely, turned it back on, and now it works…go figure