Xcode build but don't create Executable

I use a previous Xcode 3 project and built it successfully on the Mac SDK 10.6.

What I don't understand is that not any executable is generated :

• I've look at the scheme and Run is checked,
• the path to the executable I selected the previous executable for the run and then deleted that old executable to be sure开发者_如何学Python that the new will be built.

Strangely, no executable is built.

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Xcode 4 changes the default build location. It's no longer going into $(SRCROOT)/build, but ~/Library/Xcode/DerivedData/... where ... is a project-specific folder. Right-click the executable in Xcode and choose "Show in Finder".