Upgrade to latest Rust

- std::os -> std::env

1 files changed, 1 insertions, 1 deletions

diff --git a/src/options.rs b/src/options.rs
index d37af1e..ddf87bd 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -175,7 +175,7 @@ pub enum Misfire {
 
 impl Misfire {
     /// The OS return code this misfire should signify.
-    pub fn error_code(&self) -> isize {
+    pub fn error_code(&self) -> i32 {
         if let Help(_) = *self { 2 }
                           else { 3 }
     }