bARMy types error

[MagaTailor]

This breakage is responsible for errors like these on ARM Linux:

Compiling nix v0.3.9
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/fcntl.rs:102:28: 102:41 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/fcntl.rs:102         unsafe { ffi::open(cstr.as_ptr(), oflag.bits(), mode.bits() as mode_t) }
                                                                                                               ^~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/fcntl.rs:101:14: 103:8 note: in this expansion of try! (defined in <std macros>)
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/fcntl.rs:102:28: 102:41 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:105:30: 105:43 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:105         unsafe { ffi::umount(cstr.as_ptr()) }
                                                                                                                 ^~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:104:15: 106:8 note: in this expansion of try! (defined in <std macros>)
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:105:30: 105:43 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:113:31: 113:44 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:113         unsafe { ffi::umount2(cstr.as_ptr(), flags.bits) }
                                                                                                                  ^~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:112:15: 114:8 note: in this expansion of try! (defined in <std macros>)
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mount.rs:113:31: 113:44 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:80:37: 80:50 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:80     let res = unsafe { ffi::mq_open(name.as_ptr(), oflag.bits(), mode.bits() as mode_t, attr as *const MqAttr) };
                                                                                                                        ^~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:80:37: 80:50 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:90:39: 90:52 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:90     let res = unsafe { ffi::mq_unlink(name.as_ptr()) };
                                                                                                                          ^~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:90:39: 90:52 help: run `rustc --explain E0308` to see a detailed explanation
   Compiling env_logger v0.3.2
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:112:31: 112:47 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:112     let len = unsafe { strlen(message.as_ptr()) as size_t };
                                                                                                                   ^~~~~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:112:31: 112:47 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:113:44: 113:60 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:113     let res = unsafe { ffi::mq_send(mqdes, message.as_ptr(), len, msq_prio) };
                                                                                                                                ^~~~~~~~~~~~~~~~
/home/odroid/.cargo/git/checkouts/nix-rust-410e385daf3c9671/master/src/mqueue.rs:113:44: 113:60 help: run `rustc --explain E0308` to see a detailed explanation
/home/odroid/.cargo/registry/src/git.colasdn.top-48ad6e4054423464/nix-0.3.9/src/fcntl.rs:74:28: 74:41 error: mismatched types:
 expected `*const i8`,
    found `*const u8`
(expected i8,
    found u8) [E0308]

In most cases they can be fixed by simple casts as *const _

[chengchangwu]

Same problem here with nix-rust v0.4.2. Please upgrade to libc v0.2.

[MagaTailor]

The latest master seems to be free of this issue.

[kamalmarhubi]

Thanks for checking @petevine!

[thkaw]

Still have some dependency problem when build ARM

nix still using libc 0.1.12 in nix 0.4.2?

Build in Rust 1.6.0 (c30b771ad 2016-01-19)

[kamalmarhubi]

The latest master is using 0.2.6, but the latest release is still on 0.1.x as you noticed. We're figuring out how to make a release this week (#269), so hopefully there will soon be a 0.5.0 that uses libc 0.2.x, and includes the ARM fixes.

[MagaTailor]

It might make sense to fix the < 0.5 series too.

I recently tried overriding this dependency with master and that immediately broke mio.

[thkaw]

Ok, I do little modified on mio v0.5.0.
It will make mio able to using latest nix in master.(0.5.1-pre)

Mio:
thkaw/mio@8add138

[kamalmarhubi]

@petevine sadly there are no git tags for earlier releases. If we could figure out when 0.4.2 was cut, we might be able to make a fix and release a 0.4.3. The bump to libc 0.2 series was in #219, so that could be another alternative to cut a 0.4.3. My personal preference would be leave the 0.4 series behind, but that's biased by me starting to use nix, and joining the team more recently.

Going forward, we should soon have CI on ARM, which we'll then keep green. Track #258 for that.

Reopening for some discussion.

[posborne]

0.4.2 is dated Dec 3, 2015, so I would guess b4b76d0 as the next change was a breaking one.

ARM CI support is still a WIP but progress is under way.

[kamalmarhubi]

@petevine, there is now a 0.5.0. I haven't given fixing 0.4 series a shot yet.

[MagaTailor]

@kamalmarhubi I've just confirmed the latest nix/mio combo works on ARM; I'd like to update dependencies of the parity project but nix 0.5.0 looks 2 months old already - should I use it anyway or wait for the next release?

[kamalmarhubi]

If 0.5.0 works, use it. We haven't yet figured out how to do releases without @carllerche. Filed #363 to track the unreleasability.

[kamalmarhubi]

(@petevine forgot to mention you)