error[E0412]: cannot find type `pid_t` in crate `libc`
   --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:21:18
    |
21 | Parent(libc::pid_t),
    | ^^^^^ not found in `libc`

error[E0425]: cannot find function `fork` in crate `libc`
    --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:112:30
     |
112 | let res = unsafe { libc::fork() };
     | ^^^^ not found in `libc`

error[E0412]: cannot find type `pid_t` in crate `libc`
    --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:128:33
     |
128 | pub fn setsid() -> Result<libc::pid_t, i32> {
     | ^^^^^ not found in `libc`

error[E0425]: cannot find function `setsid` in crate `libc`
    --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:129:30
     |
129 | let res = unsafe { libc::setsid() };
     | ^^^^^^ help: a function with a similar name exists: `getpid`
     |
    ::: C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\libc-0.2.149\src\windows\mod.rs:491:5
     |
491 | pub fn getpid() -> ::c_int;
     | -------------------------- similarly named function `getpid` defined here

error[E0412]: cannot find type `pid_t` in crate `libc`
    --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:140:34
     |
140 | pub fn getpgrp() -> Result<libc::pid_t, i32> {
     | ^^^^^ not found in `libc`

error[E0425]: cannot find function `getpgrp` in crate `libc`
    --> C:\Users\l-7-l\.cargo\registry\src\index.crates.io-6f17d22bba15001f\fork-0.1.22\src\lib.rs:141:30
     |
141 | let res = unsafe { libc::getpgrp() };
     | ^^^^^^^ not found in `libc`

Some errors have detailed explanations: E0412, E0425.
For more information about an error, try `rustc --explain E0412`.