Do not use LFS64 on linux with musl

[kraj]

glibc is providing open64 and other lfs64 functions but musl aliases them to normal equivalents since off_t is always 64-bit on musl, therefore check for target env along when target OS is linux before using open64, this is more available. Latest Musl has made these namespace changes [1]

[1] https://git.musl-libc.org/cgit/musl/commit/?id=246f1c811448f37a44b41cd8df8d0ef9736d95f4

[rustbot]

r? @thomcc

(rustbot has picked a reviewer for you, use r? to override)

[rustbot]

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

• Stabilizing library features
• Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
• Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
• Changing public documentation in ways that create new stability guarantees
• Changing observable runtime behavior of library APIs

[thomcc]

@rustbot author

Please use at-rustbot ready to push it back into my review queue when it is ready.

[JohnCSimon]

@kraj
Ping from triage - can you please address the reviewer's comments?

[bors]

☔ The latest upstream changes (presumably #106673) made this pull request unmergeable. Please resolve the merge conflicts.

[kraj]

@kraj Ping from triage - can you please address the reviewer's comments?

yeah I need to find time to rework this.

[alyssais]

Any news here? This is our main barrier to upgrading to musl 1.2.4 in Nixpkgs.

[rust-log-analyzer]

The job x86_64-gnu-tools failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

    |
299 | pub struct DirEntry {
    | ------------------- previous definition of the type `DirEntry` here
...
336 | pub struct DirEntry {
    | ^^^^^^^^^^^^^^^^^^^ `DirEntry` redefined here
    |
    = note: `DirEntry` must be defined only once in the type namespace of this module
error[E0432]: unresolved import `libc::fstatat64`
  --> /checkout/library/std/src/sys/unix/fs.rs:57:5
   |
57 | use libc::fstatat64;
57 | use libc::fstatat64;
   |     ^^^^^^---------
   |     |     |
   |     |     help: a similar name exists in the module: `fstatat`
   |     no `fstatat64` in the root

error[E0432]: unresolved imports `libc::dirent64`, `libc::fstat64`, `libc::ftruncate64`, `libc::lseek64`, `libc::lstat64`, `libc::off64_t`, `libc::open64`, `libc::stat64`
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek64, lstat64, off64_t, open64, stat64};
    |            |         |        |            |        |        |        |
    |            |         |        |            |        |        |        no `open64` in the root
    |            |         |        |            |        |        no `off64_t` in the root
    |            |         |        |            |        no `lstat64` in the root
    |            |         |        |            |        no `lstat64` in the root
    |            |         |        |            no `lseek64` in the root
    |            |         |        no `ftruncate64` in the root
    |            |         no `fstat64` in the root
    |            no `dirent64` in the root
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent, fstat64, ftruncate64, lseek64, lstat64, off64_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat, ftruncate64, lseek64, lstat64, off64_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate, lseek64, lstat64, off64_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek, lstat64, off64_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek64, lstat, off64_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek64, lstat64, off_t, open64, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek64, lstat64, off64_t, open, stat64};
help: a similar name exists in the module
    |
    |
106 | use libc::{dirent64, fstat64, ftruncate64, lseek64, lstat64, off64_t, open64, stat};

error[E0412]: cannot find type `dirent64_min` in this scope
    --> /checkout/library/std/src/sys/unix/fs.rs:301:12
     |
     |
301  |       entry: dirent64_min,
     |              ^^^^^^^^^^^^ help: a struct with a similar name exists: `dirent64`
     |
    ::: /cargo/registry/src/index.crates.io-6f17d22bba15001f/libc-0.2.143/src/unix/bsd/apple/mod.rs:1105:1
     |
1105 | / s_no_extra_traits! {
1106 | |     #[cfg_attr(libc_packedN, repr(packed(4)))]
1107 | |     pub struct kevent {
1108 | |         pub ident: ::uintptr_t,
1383 | |     }
1384 | | }
     | |_- similarly named struct `dirent64` defined here


error[E0063]: missing field `name` in initializer of `sys::unix::fs::DirEntry`
   --> /checkout/library/std/src/sys/unix/fs.rs:768:27
    |
768 |             let mut ret = DirEntry { entry: mem::zeroed(), dir: Arc::clone(&self.inner) };
    |                           ^^^^^^^^ missing `name`
Some errors have detailed explanations: E0063, E0412, E0428, E0432.
For more information about an error, try `rustc --explain E0063`.
error: could not compile `std` (lib) due to 5 previous errors
fatal error: failed to build sysroot: sysroot build failed

[Dylan-DPC]

@kraj any updates on this?

[git-bruh]

Hey, can I take over this PR?

[Dylan-DPC]

@git-bruh sure feel free to submit a new pr and link to this one

[kraj]

Hey, can I take over this PR?

Please go ahead I won’t have time soon to work on it