Auto merge of #4241 - Keruspe:rust-1.19.0, r=alexcrichton

[beta] hash '__CARGO_DEFAULT_LIB_METADATA' in metadata for rustc

This is a backport of #4239 for beta

src/cargo/ops/cargo_rustc/context.rs

@@ -442,16 +442,17 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
         // Note, though, that the compiler's build system at least wants
         // path dependencies (eg libstd) to have hashes in filenames. To account for
         // that we have an extra hack here which reads the
-        // `__CARGO_DEFAULT_METADATA` environment variable and creates a
+        // `__CARGO_DEFAULT_LIB_METADATA` environment variable and creates a
         // hash in the filename if that's present.
         //
         // This environment variable should not be relied on! It's
         // just here for rustbuild. We need a more principled method
         // doing this eventually.
+        let __cargo_default_lib_metadata = env::var("__CARGO_DEFAULT_LIB_METADATA");
         if !unit.profile.test &&
             (unit.target.is_dylib() || unit.target.is_cdylib()) &&
             unit.pkg.package_id().source_id().is_path() &&
-            !env::var("__CARGO_DEFAULT_LIB_METADATA").is_ok() {
+            !__cargo_default_lib_metadata.is_ok() {
             return None;
         }
 
@@ -491,6 +492,12 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
             rustc.verbose_version.hash(&mut hasher);
         }
 
+        // Seed the contents of __CARGO_DEFAULT_LIB_METADATA to the hasher if present.
+        // This should be the release channel, to get a different hash for each channel.
+        if let Ok(ref channel) = __cargo_default_lib_metadata {
+            channel.hash(&mut hasher);
+        }
+
         Some(Metadata(hasher.finish()))
     }
 

tests/bench.rs

@@ -242,10 +242,10 @@ fn cargo_bench_failing_test() {
 [FINISHED] release [optimized] target(s) in [..]
 [RUNNING] target[/]release[/]deps[/]foo-[..][EXE]
 thread '[..]' panicked at 'assertion failed: \
-    `(left == right)` (left: \
-    `\"hello\"`, right: `\"nope\"`)', src[/]foo.rs:14
-[..]
-", p.url()))
+    `(left == right)`[..]", p.url()))
+                       .with_stderr_contains("[..]left: `\"hello\"`[..]")
+                       .with_stderr_contains("[..]right: `\"nope\"`[..]")
+                       .with_stderr_contains("[..]src[/]foo.rs:14")
                        .with_status(101));
 }
 

tests/build.rs

@@ -849,7 +849,7 @@ suffix = env::consts::DLL_SUFFIX,
     assert_that(p.cargo("clean"), execs().with_status(0));
 
     // If you set the env-var, then we expect metadata on libbar
-    assert_that(p.cargo("build").arg("-v").env("__CARGO_DEFAULT_LIB_METADATA", "1"),
+    assert_that(p.cargo("build").arg("-v").env("__CARGO_DEFAULT_LIB_METADATA", "stable"),
                 execs().with_status(0).with_stderr(&format!("\
 [COMPILING] bar v0.0.1 ({url}/bar)
 [RUNNING] `rustc --crate-name bar bar[/]src[/]lib.rs --crate-type dylib \

tests/test.rs

@@ -215,10 +215,11 @@ test test_hello ... FAILED
 failures:
 
 ---- test_hello stdout ----
-<tab>thread 'test_hello' panicked at 'assertion failed: \
-    `(left == right)` (left: \
-    `\"hello\"`, right: `\"nope\"`)', src[/]foo.rs:12
-")
+<tab>thread 'test_hello' panicked at 'assertion failed:[..]")
+                       .with_stdout_contains("[..]`(left == right)`[..]")
+                       .with_stdout_contains("[..]left: `\"hello\"`,[..]")
+                       .with_stdout_contains("[..]right: `\"nope\"`[..]")
+                       .with_stdout_contains("[..]src[/]foo.rs:12[..]")
                        .with_stdout_contains("\
 failures:
     test_hello