fix tests on HFS

tests/testsuite/freshness.rs

@@ -1193,6 +1193,7 @@ fn simple_deps_cleaner(mut dir: PathBuf, timestamp: filetime::FileTime) {
         let dep = dep.unwrap();
         if filetime::FileTime::from_last_modification_time(&dep.metadata().unwrap()) <= timestamp {
             fs::remove_file(dep.path()).unwrap();
+            println!("remove: {:?}", dep.path());
             cleand = true;
         }
     }
@@ -1235,6 +1236,9 @@ fn simple_deps_cleaner_dose_not_rebuild() {
         sleep_ms(1000);
     }
     let timestamp = filetime::FileTime::from_system_time(SystemTime::now());
+    if is_coarse_mtime() {
+        sleep_ms(1000);
+    }
     // This dose not make new files, but it dose update the mtime.
     p.cargo("build")
         .env("RUSTFLAGS", "-C target-cpu=native")
@@ -1275,6 +1279,7 @@ fn fingerprint_cleaner(mut dir: PathBuf, timestamp: filetime::FileTime) {
                 <= timestamp
         }) {
             fs::remove_dir_all(fing.path()).unwrap();
+            println!("remove: {:?}", fing.path());
             // a real cleaner would remove the big files in deps and build as well
             // but fingerprint is sufficient for our tests
             cleand = true;
@@ -1320,6 +1325,9 @@ fn fingerprint_cleaner_dose_not_rebuild() {
         sleep_ms(1000);
     }
     let timestamp = filetime::FileTime::from_system_time(SystemTime::now());
+    if is_coarse_mtime() {
+        sleep_ms(1000);
+    }
     // This dose not make new files, but it dose update the mtime.
     p.cargo("build")
         .env("RUSTFLAGS", "-C target-cpu=native")

tests/testsuite/support/mod.rs

@@ -1603,6 +1603,9 @@ pub fn sleep_ms(ms: u64) {
 
 /// Returns true if the local filesystem has low-resolution mtimes.
 pub fn is_coarse_mtime() -> bool {
+    // If the filetime crate is being used to emulate HFS then
+    // return true, without looking at the actual hardware.
+    cfg!(emulate_second_only_system) ||
     // This should actually be a test that $CARGO_TARGET_DIR is on an HFS
     // filesystem, (or any filesystem with low-resolution mtimes). However,
     // that's tricky to detect, so for now just deal with CI.