Auto merge of #6561 - ehuss:fix-switch-features, r=alexcrichton

Fix spurious Windows errors with switch_features_rerun. Fix a flaky test on Windows which fails with "Access is denied.". Previous errors: https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/17766698 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18040797 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/20472056 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18746372 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18559776 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/19659571 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18956349 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18183191 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/20334485 https://ci.appveyor.com/project/rust-lang-libs/cargo/builds/18554058
rust-lang · Jan 18, 2019 · 286896f · 286896f
2 parents 87dd6c2 + 2a1adb3
commit 286896f
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 18 deletions.
diff --git a/tests/testsuite/build_script.rs b/tests/testsuite/build_script.rs
@@ -3171,9 +3171,12 @@ fn switch_features_rerun() {
         )
         .build();
 
-    p.cargo("run -v --features=foo").with_stdout("foo\n").run();
-    p.cargo("run -v").with_stdout("bar\n").run();
-    p.cargo("run -v --features=foo").with_stdout("foo\n").run();
+    p.cargo("build -v --features=foo").run();
+    p.rename_run("foo", "with_foo").with_stdout("foo\n").run();
+    p.cargo("build -v").run();
+    p.rename_run("foo", "without_foo").with_stdout("bar\n").run();
+    p.cargo("build -v --features=foo").run();
+    p.rename_run("foo", "with_foo2").with_stdout("foo\n").run();
 }
 
 #[test]

diff --git a/tests/testsuite/freshness.rs b/tests/testsuite/freshness.rs
@@ -447,17 +447,6 @@ fn changing_bin_features_caches_targets() {
         )
         .build();
 
-    // Windows has a problem with replacing a binary that was just executed.
-    // Unlinking it will succeed, but then attempting to immediately replace
-    // it will sometimes fail with "Already Exists".
-    // See https://github.com/rust-lang/cargo/issues/5481
-    let foo_proc = |name: &str| {
-        let src = p.bin("foo");
-        let dst = p.bin(name);
-        fs::rename(&src, &dst).expect("Failed to rename foo");
-        p.process(dst)
-    };
-
     p.cargo("build")
         .with_stderr(
             "\
@@ -466,7 +455,7 @@ fn changing_bin_features_caches_targets() {
 ",
         )
         .run();
-    foo_proc("off1").with_stdout("feature off").run();
+    p.rename_run("foo", "off1").with_stdout("feature off").run();
 
     p.cargo("build --features foo")
         .with_stderr(
@@ -476,7 +465,7 @@ fn changing_bin_features_caches_targets() {
 ",
         )
         .run();
-    foo_proc("on1").with_stdout("feature on").run();
+    p.rename_run("foo", "on1").with_stdout("feature on").run();
 
     /* Targets should be cached from the first build */
 
@@ -487,7 +476,7 @@ fn changing_bin_features_caches_targets() {
 ",
         )
         .run();
-    foo_proc("off2").with_stdout("feature off").run();
+    p.rename_run("foo", "off2").with_stdout("feature off").run();
 
     p.cargo("build --features foo")
         .with_stderr(
@@ -496,7 +485,7 @@ fn changing_bin_features_caches_targets() {
 ",
         )
         .run();
-    foo_proc("on2").with_stdout("feature on").run();
+    p.rename_run("foo", "on2").with_stdout("feature on").run();
 }
 
 #[test]

diff --git a/tests/testsuite/support/mod.rs b/tests/testsuite/support/mod.rs
@@ -399,6 +399,27 @@ impl Project {
         execs
     }
 
+    /// Safely run a process after `cargo build`.
+    ///
+    /// Windows has a problem where a process cannot be reliably
+    /// be replaced, removed, or renamed immediately after executing it.
+    /// The action may fail (with errors like Access is denied), or
+    /// it may succeed, but future attempts to use the same filename
+    /// will fail with "Already Exists".
+    ///
+    /// If you have a test that needs to do `cargo run` multiple
+    /// times, you should instead use `cargo build` and use this
+    /// method to run the executable. Each time you call this,
+    /// use a new name for `dst`.
+    /// See https://github.com/rust-lang/cargo/issues/5481
+    pub fn rename_run(&self, src: &str, dst: &str) -> Execs {
+        let src = self.bin(src);
+        let dst = self.bin(dst);
+        fs::rename(&src, &dst)
+            .unwrap_or_else(|e| panic!("Failed to rename `{:?}` to `{:?}`: {}", src, dst, e));
+        self.process(dst)
+    }
+
     /// Returns the contents of `Cargo.lock`.
     pub fn read_lockfile(&self) -> String {
         self.read_file("Cargo.lock")