LD_PRELOAD=blockdebugdetect.so strace ./testDebug

blockdebugdetect.c

/* Simple source code for a library to prevent apps being able to see if they're running under debug
 * compile as follows:
 * gcc -shared -fPIC blockdebugdetect.c -o blockdebugdetect.so 
 * then use LD_PRELOAD to override as follows:
 * LD_PRELOAD=blockdebugdetect.so strace ./testDebug
 */

long ptrace(int request, int pid, void *addr, void *data)
{
    /* Nope - we're definitely not running under a debugger mwaahahahahaa */
    return 0;
}

#if 0
typedef void (*sighandler_t)(int);
sighandler_t signal(int signum, sighandler_t handler)
{
    /* This assumes they're also preventing SIGTRAP/int3 from being inserted so stub that out too */
    return NULL;
}
#endif