Compilation error on Apple Silicon Mac

[poetaman]

>> cargo install fcat --verbos
.
.
.
     Running `rustc --crate-name fcat /Users/reportaman/.cargo/registry/src/github.com-1ecc6299db9ec823/fcat-0.1.0/src/main.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C opt-level=3 -C embed-bitcode=no -C metadata=170953d2de8e5e5f -C extra-filename=-170953d2de8e5e5f --out-dir /var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/cargo-installhV87a2/release/deps -L dependency=/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/cargo-installhV87a2/release/deps --extern nix=/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/cargo-installhV87a2/release/deps/libnix-e97ee1ac4be0467d.rlib --cap-lints allow`
error[E0432]: unresolved imports `nix::fcntl::splice`, `nix::fcntl::SpliceFFlags`
 --> /Users/reportaman/.cargo/registry/src/github.com-1ecc6299db9ec823/fcat-0.1.0/src/main.rs:8:18
  |
8 | use nix::fcntl::{splice, SpliceFFlags};
  |                  ^^^^^^  ^^^^^^^^^^^^ no `SpliceFFlags` in `fcntl`
  |                  |
  |                  no `splice` in `fcntl`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0432`.
error: failed to compile `fcat v0.1.0`, intermediate artifacts can be found at `/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/cargo-installhV87a2`

Caused by:
  could not compile `fcat`

System info:

>> neofetch
                    'c.          reportaman@Mac-mini.local 
                 ,xNMM.          ------------------------------ 
               .OMMMMo           OS: macOS 11.2 20D64 arm64 
               OMMM0,            Host: Macmini9,1 
     .;loddo:' loolloddol;.      Kernel: 20.3.0 
   cKMMMMMMMMMMNWMMMMMMMMMM0:     
 .KMMMMMMMMMMMMMMMMMMMMMMMWd.     
 XMMMMMMMMMMMMMMMMMMMMMMMX.      Shell: zsh 5.8 
;MMMMMMMMMMMMMMMMMMMMMMMM:        
:MMMMMMMMMMMMMMMMMMMMMMMM:       DE: Aqua 
.MMMMMMMMMMMMMMMMMMMMMMMMX.      WM: Quartz Compositor 
 kMMMMMMMMMMMMMMMMMMMMMMMMWd.    WM Theme: Blue (Dark) 
 .XMMMMMMMMMMMMMMMMMMMMMMMMMMk   Terminal: Apple_Terminal 
  .XMMMMMMMMMMMMMMMMMMMMMMMMK.   
    kMMMMMMMMMMMMMMMMMMMMMMd     CPU: Apple M1 
     ;KMMMMMMMWXXWMMMMMMMk.      GPU: Apple M1 
       .cooc,.    .,coo:.         

[mre]

Ah that crate is only working on Linux because it requires the splice syscall.

[poetaman]

@mre Ah ok, any plans to support macOS?

[mre]

Well, macOS provides copyfile, which seems to support COPYFILE_CLONE which will attempt to use the
APFS clone capabilities for fast copies.
mono/mono#9038
This is already supported by Rust when calling std::fs::copy. See this PR.
We could add a conditional compilation for Mac and Windows and just call std::fs:copy, which will do the right thing under the hood I guess.
It should be quite straightforward if anyone wants to give it a shot.

[mre]

Thinking about this again, it's probably not worth using fcat on anything other than Linux, though; it will not be faster than a normal copy on those OSes. :/ Closing this, but thanks a lot for trying fcat and for reporting the issue.