llvm pass error

i'm using this guide: http://llvm.org/releases/3.0/docs/WritingAnLLVMPass.html for creating an llvm pass, but i have the following error when i use

opt -load ../../../Debug+Asserts/lib/Hello.so -hello < hello.bc > /dev/null
 
 
 Error opening '../../../Release/lib/Hello.so': ../../../Release/lib/Hello.so: undefined symbol: _ZN4llvm12PassRegistry12registerPassERKNS_8PassInfoEb
   -load request ignored.
 opt: Unknown command line argument '-hello'.  Try: 'opt -help'
 

note that i haven't the folder "Debug+Asserts" but "Release"

someone know what's the problem?

maybe because for creating the Hello.bc file i use llvm-clang instead of llvm-gcc? (this guide says to use llvm-gcc but it doesn'n work: llvm.org/releases/3.0/docs/GettingStarted.html#tutorial) or maybe because i have opt version 2.8 while i'm using llvm-3.0 ?

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