I tried to install XCode via AppStore but it fails with the following message:
We could not complete your purchase
Xcode is already installed on this computer. Choose Software Update from the Apple menu to check for available updates.
This might be caused by a previous try via Download from DevelopersCenter - but as that one failed, I tried with the AppStore which is now failing too...
How can I make really remove all from the failed XCode installation to have a retry with the AppStore?
btw. I already did this:
sudo /Developer/Library/uninstall-devtools --mode=all
Many thanks!
The App Store doesn't install Xcode, exactly. What it does is to install the Xcode installer. If the installer is still in your applications folder, you can try reinstalling from that, or get rid of the installer to download it again.
来源：https://stackoverflow.com/questions/7068900/how-to-force-installation-of-xcode