Comment flock usage on Linux

rust-lang · May 21, 2020 · a05acbf · a05acbf
1 parent 564ebbb
commit a05acbf
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/librustc_data_structures/flock.rs b/src/librustc_data_structures/flock.rs
@@ -12,6 +12,11 @@ use std::io;
 use std::path::Path;
 
 cfg_if! {
+ // We use `flock` rather than `fcntl` on Linux, because WSL1 does not support
+ // `fcntl`-style advisory locks properly (rust-lang/rust#72157).
+ //
+ // For other Unix targets we still use `fcntl` because it's more portable than
+ // `flock`.
  if #[cfg(target_os = "linux")] {
  use std::os::unix::prelude::*;