Comment 2 for bug 1862263

To be clear, it's the bpf test that's causing this problem.

gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../lib/bpf -I../../../../include/generated -I../../../include -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program test_tcpnotify_user.c /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_stub.o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/libbpf.a cgroup_helpers.c trace_helpers.c -lcap -lelf -lrt -lpthread -o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_tcpnotify_user
test_tcpnotify_user.c: In function ‘main’:
test_tcpnotify_user.c:153:2: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result [-Wunused-result]
  153 | system(test_script);
      | ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:158:2: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result [-Wunused-result]
  158 | system(test_script);
      | ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:163:2: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result [-Wunused-result]
  163 | system(test_script);
      | ^~~~~~~~~~~~~~~~~~~
gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../lib/bpf -I../../../../include/generated -I../../../include -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program test_sock_fields.c /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_stub.o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/libbpf.a cgroup_helpers.c -lcap -lelf -lrt -lpthread -o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_sock_fields
gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../lib/bpf -I../../../../include/generated -I../../../include -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program test_sysctl.c /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_stub.o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/libbpf.a cgroup_helpers.c -lcap -lelf -lrt -lpthread -o /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_sysctl
test_sysctl.c:181:4: error: ‘struct sysctl_test’ has no member named ‘seek’
  181 | .seek = 4,
      | ^~~~
test_sysctl.c:181:11: warning: initialization of ‘const char *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
  181 | .seek = 4,
      | ^
test_sysctl.c:181:11: note: (near initialization for ‘tests[7].newval’)
make[1]: *** [../lib.mk:138: /home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf/test_sysctl] Error 1
make[1]: Leaving directory '/home/ubuntu/ubuntu-eoan/tools/testing/selftests/bpf'
make: *** [Makefile:137: all] Error 2

We need some module in bpf, so this was triggered in the beginning of the net test.