I need to delete all compiled data:

 - directories called `build`,
 - directories called `obj`,
 - *.so files.

I wrote a command 

 find \( -name build -o -name obj -o -name *.so \) -exec rm -rf {} \;

that goes through all the directories recursively and deletes all I need.

Why do I have such an output at the end?
Maybe I should write a different command.

 find: `./3/obj': No such file or directory
 find: `./3/build': No such file or directory
 find: `./1/obj': No such file or directory
 find: `./1/build': No such file or directory
 find: `./2/obj': No such file or directory
 find: `./2/build': No such file or directory