Question

stap -g -a mips -p4 -B CROSS_COMPILE=mipsel-linux- \
         -m hello -e 'probe begin {print("hello! \n") exit()}'

In file included from ./arch/mips/include/asm/bug.h:4,
                 from include/linux/bug.h:4,
                 from include/linux/mmdebug.h:4,
                 from include/linux/gfp.h:4,
                 from /usr/local/share/systemtap/runtime/linux/runtime_defines.h:20,
                 from /usr/local/share/systemtap/runtime/runtime_defines.h:8,
                 from /tmp/stapaU6vwh/hello_src.c:12:
/usr/local/share/systemtap/runtime/transport/relay_v2.c: In function ‘__stp_relay_switch_subbuf’:
/usr/local/share/systemtap/runtime/transport/relay_v2.c:69:34: error: invalid use of undefined type ‘struct rchan_buf’
   69 |         if (unlikely(length > buf->chan->subbuf_size))
      |                                  ^~
include/linux/compiler.h:166:45: note: in definition of macro ‘unlikely’
  166 | # define unlikely(x)    __builtin_expect(!!(x), 0)
      |                                             ^
In file included from /usr/local/share/systemtap/runtime/transport/transport.c:70,
                 from /usr/local/share/systemtap/runtime/linux/print.c:17,
                 from /usr/local/share/systemtap/runtime/print.c:17,
                 from /usr/local/share/systemtap/runtime/runtime_context.h:22,
                 from /tmp/stapaU6vwh/hello_src.c:49:

Answer

CONFIG_RELAY=y