Build error referencing build.xml and proguard file: “null returned: 1”

Question

While building my PhoneGap app (with the Facebook SDK plugin installed), I encountered this error:

BUILD FAILED C:\\adt-bundle-windows-x86_64-201305

Answer 1

For me, conflicting build targets were at fault. Needed to change project.properties in my library directory (which was appcompat) to 'target=android-21', instead of android-19 which I had before. If you encounter a similar error and the previous answer (ant clean) does not work, check all the build targets.