If the launch came from the Finder, the Carbon process serial number is placed in argv (to see what I mean do a ps -ax and notice the - psn_* arguments). Let me dig some more after I drop the teenager off at school. On May 1, 2008, at 7:17 AM, Michael Haupt wrote:

Dear all,

today, I came across some interesting (and, so far, unsettling) behaviour of the Carbon VM (on Mac OS X, of course).

The scenario is this: inside the image, OSProcess is used to start a Python script that goes to daemon state after some time. The command line passed to OSProcess>>#waitForCommand: is 'python /path/to/script.py -some -args'.

Here's the interesting bit.

The OSProcess has an exit value of 256 (and does not work) when I start the image the "normal" way, i.e., by double-clicking it, or by drag-and-dropping it to a VM, or by issuing "open -a /path/to/SqueakVM.app my.image". The VM process, as shown by "ps x", looks like this: "/path/to/Squeak VM Opt.app/Contents/MacOS/Squeak VM Opt -psn_0_4199425".

Conversely, when I start the same image by first starting the VM, either by double-clicking it or by starting it directly from the terminal command line ("open /path/to/SqueakVM.app" or "/path/to/SqueakVM.app/Contents/MacOS/Squeak\ VM\ Opt"), and then selecting the image from the file selection dialogue, everything is fine. The VM process, then, looks like this: "/path/to/Squeak VM Opt.app/Contents/MacOS/Squeak VM Opt" (i.e., without the "-psn...").

What is the difference, and why? I'm puzzled. Someone, please enlighten me. :-)

Best,

Michael

-- = = = ======================================================================== John M. McIntosh johnmci@smalltalkconsulting.com Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com = = = ========================================================================

On Thu, May 01, 2008 at 04:17:42PM +0200, Michael Haupt wrote:

Dear all,

today, I came across some interesting (and, so far, unsettling) behaviour of the Carbon VM (on Mac OS X, of course).

I'm pretty sure we are not going to be able to blame this one on the VM ;-)

The scenario is this: inside the image, OSProcess is used to start a Python script that goes to daemon state after some time. The command line passed to OSProcess>>#waitForCommand: is 'python /path/to/script.py -some -args'.

Here's the interesting bit.

The OSProcess has an exit value of 256 (and does not work) when I start the image the "normal" way, i.e., by double-clicking it, or by drag-and-dropping it to a VM, or by issuing "open -a /path/to/SqueakVM.app my.image". The VM process, as shown by "ps x", looks like this: "/path/to/Squeak VM Opt.app/Contents/MacOS/Squeak VM Opt -psn_0_4199425".

The #waitForCommand: method uses /bin/sh to run your Python interpreter, so the exit status is that of the /bin/sh process. That means that the /bin/sh had some problem finding or running python, but it does not tell you much about what the problem was.

Conversely, when I start the same image by first starting the VM, either by double-clicking it or by starting it directly from the terminal command line ("open /path/to/SqueakVM.app" or "/path/to/SqueakVM.app/Contents/MacOS/Squeak\ VM\ Opt"), and then selecting the image from the file selection dialogue, everything is fine. The VM process, then, looks like this: "/path/to/Squeak VM Opt.app/Contents/MacOS/Squeak VM Opt" (i.e., without the "-psn...").

What is the difference, and why? I'm puzzled. Someone, please enlighten me. :-)

To look at the command line arguments and $PATH for your VM, use these: OSProcess thisOSProcess arguments. OSProcess thisOSProcess path.

Do you have CommandShell loaded in addition to OSProcess? If so, this will probably lead you directly to the source of the problem:

(CommandShell pipeline: 'python /path/to/script.py -some -args') errorUpToEnd inspect

Or the same basic thing broken down in steps:

| p | p := CommandShell pipeableProxyFor: 'python /path/to/script.py -some -args'. p value. [p isComplete] whileFalse: [(Delay forMilliseconds: 20) wait]. p errorUpToEnd inspect.

Dave