Repro

Author: ehuss

crates/cargo-test-support/src/registry.rs

@@ -145,6 +145,7 @@ pub struct Package {
     alternative: bool,
     invalid_json: bool,
     proc_macro: bool,
+    links: Option<String>,
 }
 
 #[derive(Clone)]
@@ -245,6 +246,7 @@ impl Package {
             alternative: false,
             invalid_json: false,
             proc_macro: false,
+            links: None,
         }
     }
 
@@ -368,6 +370,11 @@ impl Package {
         self
     }
 
+    pub fn links(&mut self, links: &str) -> &mut Package {
+        self.links = Some(links.to_string());
+        self
+    }
+
     /// Creates the package and place it in the registry.
     ///
     /// This does not actually use Cargo's publishing system, but instead
@@ -420,6 +427,7 @@ impl Package {
             "cksum": cksum,
             "features": self.features,
             "yanked": self.yanked,
+            "links": self.links,
         })
         .to_string();
 

tests/testsuite/build.rs

@@ -4929,3 +4929,58 @@ hello stderr!
     let stdout = spawn(true);
     lines_match("hello_stdout!", &stdout);
 }
+
+use cargo_test_support::registry::Dependency;
+
+#[cargo_test]
+fn eric() {
+    Package::new("blas-src", "0.6.1")
+        .add_dep(Dependency::new("openblas-src", "0.9").optional(true))
+        .feature("openblas", &["openblas-src"])
+        .publish();
+    Package::new("openblas-src", "0.9.0")
+        .links("openblas")
+        .publish();
+    Package::new("openblas-src", "0.6.1")
+        .links("openblas")
+        .publish();
+    Package::new("ndarray-linalg", "0.12.0")
+        .add_dep(&Dependency::new("blas-src", "0.4")) // default-features=false
+        .add_dep(Dependency::new("ndarray", "0.13").enable_features(&["blas"]))
+        .publish();
+    Package::new("blas-src", "0.4.0").publish();
+    Package::new("blas-src", "0.2.1")
+        .feature("openblas", &["openblas-src"])
+        .add_dep(Dependency::new("openblas-src", "0.6").optional(true))
+        .publish();
+    Package::new("ndarray", "0.13.1")
+        .add_dep(Dependency::new("blas-src", "0.2.0").optional(true))
+        .feature("blas", &["blas-src"])
+        .publish();
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+
+                [dependencies]
+                blas-src = { version = "*", features = ["openblas"] }
+                openblas-src = { version = "*" }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+
+    p.cargo("generate-lockfile").run();
+    cargo::util::paths::append(&p.root().join("Cargo.toml"), b"ndarray-linalg = \"0.12\"\n")
+        .unwrap();
+    p.cargo("check")
+        .with_status(101)
+        .with_stderr_contains("[..]links to the native library `openblas`[..]")
+        .run();
+    // This passes, what!?
+    p.cargo("check").run();
+}