From 3bd521786acf1b649a692d6c8a6c795fe02772c5 Mon Sep 17 00:00:00 2001
From: Brian Smith <brian@briansmith.org>
Date: Mon, 16 Mar 2026 13:47:42 -0700
Subject: [PATCH] Use windows backend for cygwin target.

Cygwin's `getrandom` implementation is doing the job of the
`getrandom` crate. Instead, we can just bypass it and do our own
job ourselves. By default, use the `windows` backend, but also allow
the `windows_legacy` backend to be used if requested.
---
 src/backends.rs                | 3 +--
 src/backends/windows_legacy.rs | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/backends.rs b/src/backends.rs
index 95547d9d3..441623bd1 100644
--- a/src/backends.rs
+++ b/src/backends.rs
@@ -112,7 +112,6 @@ cfg_if! {
         target_os = "freebsd",
         target_os = "hurd",
         target_os = "illumos",
-        target_os = "cygwin",
         // Check for target_arch = "arm" to only include the 3DS. Does not
         // include the Nintendo Switch (which is target_arch = "aarch64").
         all(target_os = "horizon", target_arch = "arm"),
@@ -161,7 +160,7 @@ cfg_if! {
     } else if #[cfg(all(windows, target_vendor = "win7"))] {
         mod windows_legacy;
         pub use windows_legacy::*;
-    } else if #[cfg(windows)] {
+    } else if #[cfg(any(windows, target_os = "cygwin"))] {
         mod windows;
         pub use windows::*;
     } else if #[cfg(all(target_arch = "x86_64", target_env = "sgx"))] {
diff --git a/src/backends/windows_legacy.rs b/src/backends/windows_legacy.rs
index 0e917015d..77786be30 100644
--- a/src/backends/windows_legacy.rs
+++ b/src/backends/windows_legacy.rs
@@ -14,7 +14,7 @@ use core::{ffi::c_void, mem::MaybeUninit};
 
 pub use crate::util::{inner_u32, inner_u64};
 
-#[cfg(not(windows))]
+#[cfg(not(any(windows, target_os = "cygwin")))]
 compile_error!("`windows_legacy` backend can be enabled only for Windows targets!");
 
 // Binding to the Windows.Win32.Security.Authentication.Identity.RtlGenRandom