Cross compilation to arm-linux-androideabi is broken

[Darksonn]

The CI setup in Tokio has broken due to libc not providing an accept4 function on that platform. See e.g. this run

error[E0425]: cannot find function `accept4` in crate `libc`
Error:    --> /cargo/registry/src/github.com-1ecc6299db9ec823/mio-0.7.9/src/sys/unix/tcp.rs:446:18
    |
446 |           syscall!(accept4(
    |                    ^^^^^^^ help: a function with a similar name exists: `accept`
    | 
   ::: /cargo/registry/src/github.com-1ecc6299db9ec823/libc-0.2.87/src/unix/mod.rs:686:5
    |
686 | /     pub fn accept(
687 | |         socket: ::c_int,
688 | |         address: *mut sockaddr,
689 | |         address_len: *mut socklen_t,
690 | |     ) -> ::c_int;
    | |_________________- similarly named function `accept` defined here

error[E0425]: cannot find function `accept4` in crate `libc`
Error:    --> /cargo/registry/src/github.com-1ecc6299db9ec823/mio-0.7.9/src/sys/unix/uds/listener.rs:55:18
    |
55  |           syscall!(accept4(
    |                    ^^^^^^^ help: a function with a similar name exists: `accept`
    | 
   ::: /cargo/registry/src/github.com-1ecc6299db9ec823/libc-0.2.87/src/unix/mod.rs:686:5
    |
686 | /     pub fn accept(
687 | |         socket: ::c_int,
688 | |         address: *mut sockaddr,
689 | |         address_len: *mut socklen_t,
690 | |     ) -> ::c_int;
    | |_________________- similarly named function `accept` defined here

Refs: #1465

[dndll]

Can confirm same for me on libc 0.2.87

[RoastVeg]

Likewise for armv7-linux-androideabi using libc 0.2.87.

[Thomasdezeeuw]

This seems like a regression in libc..? The CI for #1468 now also fails on Android arm, which passed before.

[Thomasdezeeuw]

Confirmed that this is a regression between libc 0.2.86 and 0.2.87.

[Thomasdezeeuw]

I created rust-lang/libc#2101.

[Thomasdezeeuw]

Re-posting from #1469.

For a quick fix add the following to your Cargo.toml:

[dependencies]
libc = "=0.2.86" # Note the `=` here.

[RoastVeg]

In our cross-compilation heavy project we were more specific:

[target.'cfg(target_arch="arm", target_os="android", target_pointer_width="32")'.dependencies]
libc = "=0.2.86"

[Thomasdezeeuw]

Libc v0.2.88 is out, so after a cargo update this should all work again.