Is the installation of Xcode from App Store enough for having the developer tools?

today I tried to install the new version of Xcode. Before that I removed the developer tools with the following command:

sudo /Library/Developer/Shared/uninstall-devtools --mode=all

I also had other folder in /Library/Developer such as 4.2 4.2.1 ...

After that I installed the new Xcode and I noticed that the folder /Library/Developer contains only the Shared folder, which doesn't contain the command uninstall-devtools.

Did I install the developer tools or do I have to do something more?

Another related problem is that when I try to install Flann through Homebrew it reports the following error:

xcode-select: Error: No Xcode folder is set. Run xcode-select -switch <xcode_folder_path> to set the path to the Xcode folder.

How can I fix it?

Installing Xcode 4.3 does install the developer tools, but not for command line access. With this version, everything has been moved into the application bundle, which means there is no need for a uninstaller, since you can just delete the application. If you want to install the command line tools, open Xcode and go to Xcode > Preferences > Downloads, select the Components tab, and click the button next to Command Line Tools. (This might add an uninstaller somewhere, but I'm not sure.)

As for Homebrew, you might have to wait for an update before it supports Xcode 4.3, since everything was moved. I would suggest trying /Applications/Xcode.app as the <xcode_folder_path>, since most of the hierarchy appears to be the same.

The homebrew developers are tracking these changes in their bug database so, you may want to monitor this thread for workarounds and notification of when the homebrew system will effortlessly work with the new changes for Xcode 4.3.

Apple is providing these command line developer tools as a stand alone package now, so you may wish to get a free developer account if you don't want to wait for homebrew to change and locate / link to the new directory structure.

A nice summary of the state of affairs on Xcode 4.3.x and older as well as the upcoming changes and benefits of having the command line tools packaged by Apple officially with headers is on Kenneth Reitz's blog.

xcode-select -select "/Applications/Xcode.app" fixed this problem for me. Everything is peachy now.