user@host:~/magic$ clang -emit-llvm -g -c magicsquare.c -I ../include -I../klee/include
magicsquare.c:85:2: warning: implicit declaration of function '__assert_fail' is invalid in C99
      [-Wimplicit-function-declaration]
        klee_assert(!magic());
        ^
../klee/include/klee/klee.h:96:6: note: expanded from macro 'klee_assert'
   : __assert_fail (#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__))    \
     ^
1 warning generated.
user@host:~/magic$ time klee --libc=uclibc --posix-runtime magicsquare.bc
KLEE: NOTE: Using klee-uclibc : /home/user/klee/Release+Asserts/lib/klee-uclibc.bca
KLEE: NOTE: Using model: /home/user/klee/Release+Asserts/lib/libkleeRuntimePOSIX.bca
KLEE: output directory is "/home/user/magic/klee-out-4"
KLEE: WARNING: undefined reference to function: klee_posix_prefer_cex
KLEE: WARNING ONCE: calling external: syscall(16, 0, 21505, 38035904)
KLEE: WARNING ONCE: calling __user_main with extra arguments.
KLEE: ERROR: /home/user/magic/magicsquare.c:85: ASSERTION FAIL: !magic()
KLEE: NOTE: now ignoring this error at this location

KLEE: done: total instructions = 16605
KLEE: done: completed paths = 172
KLEE: done: generated tests = 172

real	0m52.896s
user	0m51.102s
sys	0m1.729s
user@host:~/magic$ ls klee-last/*.err
klee-last/test000153.assert.err
user@host:~/magic$ ktest-tool klee-last/test000153.ktest 
ktest file : 'klee-last/test000153.ktest'
args       : ['magicsquare.bc']
num objects: 2
object    0: name: 'model_version'
object    0: size: 4
object    0: data: '\x01\x00\x00\x00'
object    1: name: 'square'
object    1: size: 9
object    1: data: '\x04\x03\x08\t\x05\x01\x02\x07\x06'

... and, since \t == 9, that would be:
4 3 8
9 5 1
2 7 6