CCRandomGenerateBytes was added in macOS 10.10. Use arc4random_buf supplied by legacy-support.

diff --git a/library/std/src/sys/random/mod.rs b/library/std/src/sys/random/mod.rs
--- a/library/std/src/sys/random/mod.rs
+++ b/library/std/src/sys/random/mod.rs
@@ -6,6 +6,11 @@
     } else if #[cfg(target_os = "windows")] {
         mod windows;
         pub use windows::fill_bytes;
+    // Legacy macOS on PowerPC lacks CCRandomGenerateBytes (added in 10.10)
+    // Use arc4random_buf instead, available via MacPorts legacy-support
+    } else if #[cfg(all(target_vendor = "apple", any(target_arch = "powerpc", target_arch = "powerpc64")))] {
+        mod arc4random;
+        pub use arc4random::fill_bytes;
     } else if #[cfg(target_vendor = "apple")] {
         mod apple;
         pub use apple::fill_bytes;