address suggestions from acrichto

Author: nikomatsakis

src/cargo/ops/cargo_rustc/context.rs

@@ -850,9 +850,9 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
         self.lib_profile()
     }
 
-    pub fn incremental_args(&self, _unit: &Unit) -> CargoResult<Vec<String>> {
+    pub fn incremental_args(&self, unit: &Unit) -> CargoResult<Vec<String>> {
         if self.incremental_enabled {
-            Ok(vec![format!("-Zincremental={}", self.host.incremental().display())])
+            Ok(vec![format!("-Zincremental={}", self.layout(unit.kind).incremental().display())])
         } else {
             Ok(vec![])
         }

tests/build.rs

@@ -44,12 +44,14 @@ fn cargo_compile_incremental() {
     assert_that(
         p.cargo_process("build").arg("-v").env("CARGO_INCREMENTAL", "1"),
         execs().with_stderr_contains(
-            "     Running `rustc [..] -Zincremental=[..]/target/debug/incremental`\n"));
+            "[RUNNING] `rustc [..] -Zincremental=[..][/]target[/]debug[/]incremental`\n")
+            .with_status(0));
 
     assert_that(
         p.cargo_process("test").arg("-v").env("CARGO_INCREMENTAL", "1"),
         execs().with_stderr_contains(
-            "     Running `rustc [..] -Zincremental=[..]/target/debug/incremental`\n"));
+            "[RUNNING] `rustc [..] -Zincremental=[..][/]target[/]debug[/]incremental`\n")
+               .with_status(0));
 }
 
 #[test]