test failure: incomplete type for struct af_alg_iv

[tones111]

When attempting to run the test suite I get an error that struct af_alg_iv is not defined.

$ cd libc-test && cargo test
<snip>
  cargo:warning=/home/paul/src/libc/target/debug/build/libc-test-3ad7e5dad55ad485/out/main.c: In function ‘__test_fsize_af_alg_iv_iv’:
  cargo:warning=/home/paul/src/libc/target/debug/build/libc-test-3ad7e5dad55ad485/out/main.c:25567:34: error: invalid application of ‘sizeof’ to incomplete type ‘__u8[]’ {aka ‘unsigned char[]’}
  cargo:warning=25567 |                     return sizeof(foo->iv);
  cargo:warning=      |                                  ^

The offending lines in the test are

                  uint64_t __test_fsize_af_alg_iv_iv(void) {
                     struct af_alg_iv* foo = NULL;
                     return sizeof(foo->iv);
                 }

which I don't believe can ever work since dereferencing a NULL pointer is undefined behavior.

My /usr/include/linux/if_alg.h defines it as
struct af_alg_iv { __u32 ivlen; __u8 iv[]; };

Compiler explorer shows the same error when trying to implement an equivalent call. Is this a case of main.c not getting generated correctly?

system information:

$ cargo --version -v
cargo 1.68.0 (115f34552 2023-02-26)
release: 1.68.0
commit-hash: 115f34552518a2f9b96d740192addbac1271e7e6
commit-date: 2023-02-26
host: x86_64-unknown-linux-gnu
libgit2: 1.5.0 (sys:0.16.0 vendored)
libcurl: 7.86.0-DEV (sys:0.4.59+curl-7.86.0 vendored ssl:OpenSSL/1.1.1q)
os: Arch Linux [64-bit]

kernel: v6.2.7'
gcc: 12.2.1

[JohnTitor]

The cause is your kernel is too new, see torvalds/linux@94dfc73.
You could skip tests locally in this case.