Missing symbol on Linux

[j8-redis]

I've inherited a project and I'm trying to compile and use it on Linux instead of MacOS.
There are several such declarations:
pub static ROLE_CHANGED_SERVER_EVENTS_LIST: [fn(&Context, ServerRole)] = [..];
Which are subsequently called thusly:
extern "C" fn role_changed_callback(
ctx: *mut raw::RedisModuleCtx,
_eid: raw::RedisModuleEvent,
subevent: u64,
_data: *mut ::std::os::raw::c_void,
) {
let new_role = if subevent == raw::REDISMODULE_EVENT_REPLROLECHANGED_NOW_MASTER {
ServerRole::Primary
} else {
ServerRole::Replica
};
let ctx = Context::new(ctx);
ROLE_CHANGED_SERVER_EVENTS_LIST.iter().for_each(|callback| {
callback(&ctx, new_role);
});
}
All of this works fine under MacOS, but when we try to load the module in Linux we receive an error that the following symbol is missing:
__start_linkme_ROLE_CHANGED_SERVER_EVENTS_LIST

Thanks

[MeirShpilraien]

If it helps. The problem seems to be related to building using the nightly toolchain. I build with the stable toolchain and everything works fine, when I build with the nightly toolchain I get this error.

[j8-redis]

Another datapoint is that a binary cross-compiled on Mac for linux-x86_64 works fine.

[art-aier]

ubuntu 24

rustc 1.86.0-nightly (ad211ced8 2025-01-07)

  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: rust-lld: error: undefined symbol: __start_linkme_ASYNC
          >>> referenced by xboot.e5ef82106f9aab9c-cgu.0
          >>>               xboot-1c006b3c74e294c5.xboot.e5ef82106f9aab9c-cgu.0.rcgu.o:(xboot::ASYNC::h007540a0185100c5) in archive /tmp/rust/target/debug/deps/libxboot-1c006b3c74e294c5.rlib
          >>> the encapsulation symbol needs to be retained under --gc-sections properly; consider -z nostart-stop-gc (see https://lld.llvm.org/ELF/start-stop-gc)

          rust-lld: error: undefined symbol: __stop_linkme_ASYNC
          >>> referenced by xboot.e5ef82106f9aab9c-cgu.0
          >>>               xboot-1c006b3c74e294c5.xboot.e5ef82106f9aab9c-cgu.0.rcgu.o:(xboot::ASYNC::h007540a0185100c5) in archive /tmp/rust/target/debug/deps/libxboot-1c006b3c74e294c5.rlib

          rust-lld: error: undefined symbol: __start_linkm2_ASYNC
          >>> referenced by xboot.e5ef82106f9aab9c-cgu.0
          >>>               xboot-1c006b3c74e294c5.xboot.e5ef82106f9aab9c-cgu.0.rcgu.o:(xboot::ASYNC::h007540a0185100c5) in archive /tmp/rust/target/debug/deps/libxboot-1c006b3c74e294c5.rlib
          >>> the encapsulation symbol needs to be retained under --gc-sections properly; consider -z nostart-stop-gc (see https://lld.llvm.org/ELF/start-stop-gc)

          rust-lld: error: undefined symbol: __stop_linkm2_ASYNC
          >>> referenced by xboot.e5ef82106f9aab9c-cgu.0
          >>>               xboot-1c006b3c74e294c5.xboot.e5ef82106f9aab9c-cgu.0.rcgu.o:(xboot::ASYNC::h007540a0185100c5) in archive /tmp/rust/target/debug/deps/libxboot-1c006b3c74e294c5.rlib
          collect2: error: ld returned 1 exit status


error: could not compile `captcha` (test "main") due to 1 previous error
error: command `/opt/rust/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo test --no-run --message-format json-render-diagnostics --all-features` exited with code 101

use export RUSTFLAGS='-Z linker-features=-lld' will be ok

more see https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html