Dear Apple,
dtrace is very nice, but why did you remove ktrace? Whilst dtrace makes the "hard things possible", it doesn't make the "easy things easy", and often it's an easy thing that I want. Why do I need to use the Manhattan Project to crack a nut when the sledgehammer of 10.4 was more than good enough?
And if your excuse is going to be "but ktrace doesn't fit nicely with the frameworks provided with dtrace" and so "you don't really need it", well, heck, I don't really need truss on Solaris either, but that doesn't stop Sun shipping truss on Solaris as a complimentary tool.
Your OS costs money. Why are three free alternatives better here? Include one of ktrace, strace or truss in 10.6. Any will do. None will not.
Update:
It seems that the "command" I want is sudo dtruss sudo -u $USER. Yaktastik. :-(
More typing, doesn't work if the account with a problem to solve doesn't have root privileges, and I suspect will make subtle changes to the environment, compared with running the command directly.
As to my previous problem - I solved it by shipping the script in question to a Linux box and running it under strace there. Fortunately that showed the same symptoms, and strace made the cause obvious.
For future readers, the solution is likely to use dtruss. You may need to double sudo it:
sudo dtruss sudo -u rjbs
