actually fix it so cargo fix kinda works with new wrapper stuff

src/cargo/core/compiler/build_context/mod.rs

@@ -69,11 +69,14 @@ impl<'a, 'cfg> BuildContext<'a, 'cfg> {
                 }
             })?;
             rustc.push_wrapper(RustcWrapper::new(tool));
-            // } else if build_config.cargo_as_rustc_wrapper {
-            //     let mut wrapper = RustcWrapper::new(env::current_exe()?);
-            //     let prog = dbg!(rustc.path.as_os_str().to_owned());
-            //     wrapper.env("RUSTC", prog);
-            //     rustc.push_wrapper(wrapper);
+        } else if build_config.cargo_as_rustc_wrapper {
+            let mut wrapper = RustcWrapper::new(env::current_exe()?);
+            let prog = rustc.path.as_os_str().to_owned();
+            wrapper.env("RUSTC", prog);
+            for (k, v) in build_config.extra_rustc_env.iter() {
+                wrapper.env(k, v);
+            }
+            rustc.push_wrapper(wrapper);
         }
 
         let host_config = TargetConfig::new(config, &rustc.host)?;

src/cargo/core/compiler/compilation.rs

@@ -75,27 +75,11 @@ pub struct Compilation<'cfg> {
 
 impl<'cfg> Compilation<'cfg> {
     pub fn new<'a>(bcx: &BuildContext<'a, 'cfg>) -> CargoResult<Compilation<'cfg>> {
-        // If we're using cargo as a rustc wrapper then we're in a situation
-        // like `cargo fix`. For now just disregard the `RUSTC_WRAPPER` env var
-        // (which is typically set to `sccache` for now). Eventually we'll
-        // probably want to implement `RUSTC_WRAPPER` for `cargo fix`, but we'll
-        // leave that open as a bug for now.
-        let mut rustc = if bcx.build_config.cargo_as_rustc_wrapper {
-            let mut rustc = bcx.rustc.process_no_wrapper();
-            let prog = rustc.get_program().to_owned();
-            rustc.env("RUSTC", prog);
-            rustc.program(env::current_exe()?);
-            rustc
-        } else {
-            bcx.rustc.process()
-        };
+        let mut rustc = bcx.rustc.process();
 
         if bcx.config.extra_verbose() {
             rustc.display_env_vars();
         }
-        for (k, v) in bcx.build_config.extra_rustc_env.iter() {
-            rustc.env(k, v);
-        }
         for arg in bcx.build_config.extra_rustc_args.iter() {
             rustc.arg(arg);
         }

src/cargo/ops/fix.rs

@@ -593,7 +593,7 @@ impl Default for PrepareFor {
 impl FixArgs {
     fn get() -> FixArgs {
         let mut ret = FixArgs::default();
-        for arg in env::args_os().skip(1) {
+        for arg in env::args_os().skip(2) {
             let path = PathBuf::from(arg);
             if path.extension().and_then(|s| s.to_str()) == Some("rs") && path.exists() {
                 ret.file = Some(path);