manager: Add os variable since hostname on macos is weird

manager/src/error.rs

@@ -15,16 +15,16 @@ pub struct Error {
 #[derive(Debug, Error)]
 pub enum InnerError {
     #[error("IO Error: {0}")]
-    IoErr(#[from] io::Error),
+    Io(#[from] io::Error),
 
     #[error("Failed to parse template file")]
-    TemplateErr(#[from] blueprint::Error),
+    Template(#[from] blueprint::Error),
 
     #[error("Failed to parse toml file")]
-    TomlErr(#[from] toml::de::Error),
+    Toml(#[from] toml::de::Error),
 
     #[error("Unsupported variable type")]
-    TypeErr,
+    Type,
 }
 
 impl From<Vec<Error>> for Errors {