From http://build.golang.org/log/bdb16ad9a65cab92ea0c49f86bc7967ca3f3cd94:

(lldb) process continue
Process 808 resuming
(lldb) Process 808 stopped

• thread cmd/cgo: fails with gcc 4.4.1 #1: tid = 0x4d91, 0x0000bbd8 gotestmain + 764, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0) frame #0: 0x0000bbd8 gotestmain + 764
  gotest`main:
  -> 0xbbd8 <+764>: strb r2, [r3]
  0xbbdc <+768>: ldr r0, [r0]
  0xbbe0 <+772>: bl 0x13ff80 ; symbol stub for: fprintf
  0xbbe4 <+776>: movw r1, #0x1
  go_darwin_arm_exec: command timeout (test completion for 1s)
  FAIL test4
  2015/12/18 20:21:11 Failed: exit status 1

This is the code in misc/cgo/testcarchive/main2.c that does this:

    if (verbose) {
        printf("triggering SIGSEGV\n");
    }

    *nullPointer = '\0';

Is is intended to trigger a SIGSEGV, but instead on darwin/{arm,arm64} it triggers a EXC_BAD_ACCESS.