c )make error& link problem: i386:x86-64 architecture of input file, incompatible with i386 output

Question

I have this output with error message when i type "make" in terminal!!

gcc test1.o dispatchQueue.o -o test1 -pthread /usr/bin/ld: i386:x86-64 architecture of input file `test1.o' is incompatible with i386     output /usr/bin/ld: final link failed: Invalid operation collect2: ld returned 1 exit status make: *** [test1] Error 1 

Is there anyone who can explain why and how to fix it? :(

I'm attaching makefile just in case

# Comment out the targets you don't want.  # Runs all of the tests. all: test1 test2 test3 test4 test5 testFor     ./test1     ./test2     ./test3     ./test4     ./test5     ./testFor  test1: test1.o dispatchQueue.o     gcc test1.o dispatchQueue.o -o test1 -pthread  test1.o: test1.c     gcc -c test1.c  test2: test2.o dispatchQueue.o     gcc test2.o dispatchQueue.o -o test2 -pthread  test2.o: test2.c     gcc -c test2.c  test3: test3.o dispatchQueue.o     gcc test3.o dispatchQueue.o -o test3 -pthread  test3.o: test3.c     gcc -c test3.c  test4: test4.o dispatchQueue.o     gcc test4.o dispatchQueue.o -o test4 -pthread  test4.o: test4.c     gcc -c test4.c  test5: test5.o dispatchQueue.o     gcc test5.o dispatchQueue.o -o test5 -pthread  test5.o: test5.c     gcc -c test5.c  testFor: testFor.o dispatchQueue.o     gcc testFor.o dispatchQueue.o -o testFor -pthread  testFor.o: testFor.c     gcc -c testFor.c  dispatchQueue.o: dispatchQueue.c dispatchQueue.h     gcc -c dispatchQueue.c 

Answer 1

You probably have some old files (at least test1.o) compiled for i386-x64. You can remove these old files and run make again. If you can modify the Makefile try adding a line such as:

clean:     rm *.o test1 test2 test3 test4 test5 testFor 

Then when you run make clean it'll remove the old stuff, at which point you can run make again.

Answer 2

I had similar problem. Problem for me was that object files were generated with i386 arichitecture and I was trying to link with x86_64 linker. I deleted object files generated them anew with x86_64 options and tried to linking again. It works now