I checked out a copy of the sources as directed on isqueak.org and tried to build, but ran into a couple of problems.
I wanted to start with as much stability as possible so I figured I'd check out the standard VM before Cog.
First, my base SDK was missing. I googled that. Found this:
http://developer.apple.com/library/ios/#qa/qa2010/qa1701.html
Followed the instructions there. It didn't seem to change anything, but it's worth noting that I did change my settings per this article. I'm guessing what I found below overrides those settings? Anyway, it's worth noting that when I was finally able to build, I did so after following those instructions, so I'm not sure at this time whether or not they were necessary.
I don't have a 3.2 or 4.1 SDK. I searched for a bit and didn't find a place to get either one. Xcode complaints were of the form 'iphoneos4.1', so I grepped.
stratosphere:vm casey$ grep -rl iphoneos4.1 . | grep -v svn ./SqueakPureObjcCogVM.xcodeproj/project.pbxproj stratosphere:vm casey$ grep iphoneos4.1 ./SqueakPureObjcCogVM.xcodeproj/project.pbxproj SDKROOT = iphoneos4.1; SDKROOT = iphoneos4.1; SDKROOT = iphoneos4.1; SDKROOT = iphoneos4.1; SDKROOT = iphoneos4.1; SDKROOT = iphoneos4.1;
Did a search/replace-all and changed these to iphoneos4.2.
I struggled with dialog boxes complaining that Xcode detected tomfoolery on disk and wanted to overwrite my changes after modifying this file. If I did this again, I'd probably quit Xcode, make the modification with a text editor, and then reopen Xcode to build.
Once this was done, it was just a matter of resolving the dependencies on the Pharo and Squeak .sources files, and voila: I was looking at John's Obj-C bridge in the iPhone simulator with a big grin on my face.
All in all, it was a fun half hour! Now to make some tea and get to bed. Sorry if this is old news, figured I'd write it down in case it'd help anyone else:)