diff --git a/src/desktop.rs b/src/desktop.rs
index 82242460..01698af5 100644
--- a/src/desktop.rs
+++ b/src/desktop.rs
@@ -881,7 +881,9 @@ mod tests {
     impl EnvVarGuard {
         fn set(key: &'static str, value: &Path) -> Self {
             let original = env::var(key).ok();
-            std::env::set_var(key, value);
+            // std::env::{set_var, remove_var} are unsafe on newer toolchains;
+            // we limit scope here to the test helper that toggles a single key.
+            unsafe { std::env::set_var(key, value) };
             Self { key, original }
         }
     }
@@ -889,9 +891,9 @@ mod tests {
     impl Drop for EnvVarGuard {
         fn drop(&mut self) {
             if let Some(ref original) = self.original {
-                std::env::set_var(self.key, original);
+                unsafe { std::env::set_var(self.key, original) };
             } else {
-                std::env::remove_var(self.key);
+                unsafe { std::env::remove_var(self.key) };
             }
         }
     }
@@ -1108,7 +1110,8 @@ Icon=vmware-workstation\n\
         let resolved = resolve_desktop_entry(&mut cache, &ctx, &DesktopResolveOptions::default());
         assert!(resolved.icon().is_some());
         assert!(resolved.exec().is_some());
-        assert_eq!(resolved.startup_wm_class(), Some(&format!("crx_{}", id)));
+        let expected = format!("crx_{}", id);
+        assert_eq!(resolved.startup_wm_class(), Some(expected.as_str()));
     }
 
     #[test]
diff --git a/src/process.rs b/src/process.rs
index 1ad048dc..2b6c4e0e 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -9,18 +9,28 @@ use std::process::{Command, Stdio, exit};
 #[cfg(feature = "tokio")]
 use tokio::io::AsyncReadExt;
 
-#[cfg(feature = "tokio")]
 async fn read_from_pipe(read: OwnedFd) -> Option<u32> {
-    let mut read = tokio::net::unix::pipe::Receiver::from_owned_fd(read).unwrap();
-    read.read_u32().await.ok()
-}
+    #[cfg(feature = "tokio")]
+    {
+        let mut read = tokio::net::unix::pipe::Receiver::from_owned_fd(read).unwrap();
+        return read.read_u32().await.ok();
+    }
 
-#[cfg(all(feature = "smol", not(feature = "tokio")))]
-async fn read_from_pipe(read: OwnedFd) -> Option<u32> {
-    let mut read = smol::Async::new(std::fs::File::from(read)).unwrap();
-    let mut bytes = [0; 4];
-    read.read_exact(&mut bytes).await.ok()?;
-    Some(u32::from_be_bytes(bytes))
+    #[cfg(all(feature = "smol", not(feature = "tokio")))]
+    {
+        let mut read = smol::Async::new(std::fs::File::from(read)).unwrap();
+        let mut bytes = [0; 4];
+        read.read_exact(&mut bytes).await.ok()?;
+        return Some(u32::from_be_bytes(bytes));
+    }
+
+    #[cfg(not(any(feature = "tokio", feature = "smol")))]
+    {
+        use rustix::fd::AsFd;
+        let mut bytes = [0u8; 4];
+        rustix::io::read(&read, &mut bytes).ok()?;
+        return Some(u32::from_be_bytes(bytes));
+    }
 }
 
 /// Performs a double fork with setsid to spawn and detach a command.