process Debug WIP (rust-lang#42200)

Author: zackmdavis

src/libstd/process.rs

@@ -671,9 +671,6 @@ impl Command {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl fmt::Debug for Command {
-    /// Format the program and arguments of a Command for display. Any
-    /// non-utf8 data is lossily converted using the utf8 replacement
-    /// character.
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.inner.fmt(f)
     }

src/libstd/sys/unix/process/process_common.rs

@@ -81,6 +81,7 @@ pub enum ChildStdio {
     Owned(FileDesc),
 }
 
+#[derive(Debug)]
 pub enum Stdio {
     Inherit,
     Null,
@@ -351,11 +352,20 @@ fn pair_to_key(key: &OsStr, value: &OsStr, saw_nul: &mut bool) -> CString {
 
 impl fmt::Debug for Command {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{:?}", self.program)?;
-        for arg in &self.args {
-            write!(f, " {:?}", arg)?;
-        }
-        Ok(())
+        f.debug_struct("Command")
+            .field("program", &self.program)
+            .field("args", &self.args)
+            .field("env", &self.env)
+            .field("argv", &self.argv)
+            .field("envp", &self.envp)
+            .field("cwd", &self.cwd)
+            .field("uid", &self.uid)
+            .field("gid", &self.gid)
+            .field("saw_nul", &self.saw_nul)
+            .field("stdin", &self.stdin)
+            .field("stdout", &self.stdout)
+            .field("stderr", &self.stderr)
+            .finish()
     }
 }