Fortunately I just recently upgraded my DSL to 15Mb/sec. This is the first time I have actually needed it. Lion took nearly an hour and Xcode is about the same. The X install process promised 33 minutes and after 38 wall clock minutes had passed it said ‘less than one minute’, and then it started running backwards. In about 15 minutes it said ‘18 minutes remaining’. I panicked and headed for the Apple store which is 10 minutes away. By the time I got there the time estimate was decreasing again. It finished while I was at the store.

For Xcode I finally found the download button in the App Store application. It is the button under the round picture of the Lion. It is labeled ‘Installed’ on my machine now but I think it was labeled ‘Free’ when I pushed it. That started the download but I had to consult the ‘Activity Monitor’ utility to see progress. At the end I didn’t know where the result had gone to but after a while I found a file ‘Install Xcode.app’ in the Applications folder.

Near the end of Xcode installation a dialog box came up saying it was blocked until ITunes quit. I wasn't running ITunes but thanks to notes I had seen on the web while researching Xcode 4 I asked Activity Monitor about ITunes processes and politely asked that process to quit. It did and Xcode finished installing.

After the Lion install there was no gcc in my PATH. After Xcode install there was and it correctly compiled a fairly complex C program with nested functions. It also crashed on a trivial and useless, but valid C program. I reported the bug #9832181.