Xcode: Warning: Multiple build commands for output file AND error: unable to open executable ''

Question

I've been reading countless other posts and trying numerous fixes, but nothing has worked for my problem. I'll preface this by saying that I haven't used Xcode on this Macbook in some 2-3 months. This is the only project (out of the 4 or so I've tried) that has this problem. The first thing I did after opening Xcode was I changed the name of the project as well as a .h and .m file. I did all of this through Xcode, not Finder.

Nothing is appearing in the Navigator in red text which would indicate that it can't be found. Here is what I've already tried (many times).

Close/Open Xcode.
Clean both the project and build folder.
Delete Derived Data folder.
Ran a Disk Utility to repair permissions.
Restarted the computer.
Tried different combinations of Code Signing.
Delete App from device.
Searched through project for any duplicate file names.

Here is the warning verbatim:

Warning: Multiple build commands for output file /Users/jinser/Library/Developer/Xcode/DerivedData/Landmarks-bgnzcomxftpffiezmwocaqdydrlj/Build/Products/Debug-iphoneos/Landmarks.app/Landmarks

and here is the error:

GenerateDSYMFile /Users/jinser/Library/Developer/Xcode/DerivedData/Landmarks-bgnzcomxftpffiezmwocaqdydrlj/Build/Products/Debug-iphoneos/Landmarks.app.dSYM /Users/jinser/Library/Developer/Xcode/DerivedData/Landmarks-bgnzcomxftpffiezmwocaqdydrlj/Build/Products/Debug-iphoneos/Landmarks.app/Landmarks cd "/Users/jinser/Desktop/Kevin/Cocos2D Projects/ARSpaceships" setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin" /Developer/usr/bin/dsymutil /Users/jinser/Library/Developer/Xcode/DerivedData/Landmarks-bgnzcomxftpffiezmwocaqdydrlj/Build/Products/Debug-iphoneos/Landmarks.app/Landmarks -o /Users/jinser/Library/Developer/Xcode/DerivedData/Landmarks-bgnzcomxftpffiezmwocaqdydrlj/Build/Products/Debug-iphoneos/Landmarks.app.dSYM

error: unable to open executable ''

This is Xcode 4.2 on Mac 10.6.8. Please, any advice would be appreciated. I am losing my mind.

Thanks.

Answer 1

So to whoever runs into this problem and all of the other solutions out there do not work for you, make sure you don't have a project folder that shares the same name as the project. For instance, my project is called Landmarks and I had a folder inside the resources also called Landmarks. Once I renamed the folder, all was well.

Answer 2

Not my answer, but LargeGlasses provided the real answer (for me) in a comment, I've formulated it as an answer in its own right because I can't Up Vote the comment.

any two files within your project that have the same name will cause this warning.

In my case, I had an icon with the same name in different subfolders, one was used by the App and the other was part of my help resource located in a different folder. The solution is to just rename one of the two.

All credit and my thanks for this answer to LargeGlasses.