flame: replace tempdir with tempfile

Similarly, `tracing-flame`'s tests also use the unmaintained `tempdir`
crate. This commit replaces it with `tempfile`.

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

tracing-flame/Cargo.toml

@@ -30,4 +30,4 @@ tracing = { path = "../tracing", version = "0.1.12", default-features = false, f
 lazy_static = "1.3.0"
 
 [dev-dependencies]
-tempdir = "0.3.7"
+tempfile = "3"

tracing-flame/tests/collapsed.rs

@@ -1,14 +1,16 @@
 use std::thread::sleep;
 use std::time::Duration;
-use tempdir::TempDir;
 use tracing::{span, Level};
 use tracing_flame::FlameLayer;
 use tracing_subscriber::{prelude::*, registry::Registry};
 
 #[test]
 fn capture_supported() {
     {
-        let tmp_dir = TempDir::new("flamegraphs").unwrap();
+        let tmp_dir = tempfile::Builder::new()
+            .prefix("tracing-flamegraph-test-")
+            .tempdir()
+            .expect("failed to create tempdir");
         let (flame_layer, _guard) =
             FlameLayer::with_file(tmp_dir.path().join("tracing.folded")).unwrap();
 
@@ -37,5 +39,7 @@ fn capture_supported() {
         }
 
         sleep(Duration::from_millis(500));
+
+        tmp_dir.close().expect("failed to delete tempdir");
     }
 }

tracing-flame/tests/concurrent.rs

@@ -1,13 +1,15 @@
 use std::thread::sleep;
 use std::time::Duration;
-use tempdir::TempDir;
 use tracing::{span, Level};
 use tracing_flame::FlameLayer;
 use tracing_subscriber::{prelude::*, registry::Registry};
 
 #[test]
 fn capture_supported() {
-    let tmp_dir = TempDir::new("flamegraphs").unwrap();
+    let tmp_dir = tempfile::Builder::new()
+        .prefix("tracing-flamegraph-test-")
+        .tempdir()
+        .expect("failed to create tempdir");
     let path = tmp_dir.path().join("tracing.folded");
     let (flame_layer, flame_guard) = FlameLayer::with_file(&path).unwrap();
 
@@ -37,4 +39,6 @@ fn capture_supported() {
     let traces = std::fs::read_to_string(&path).unwrap();
     println!("{}", traces);
     assert_eq!(5, traces.lines().count());
+
+    tmp_dir.close().expect("failed to delete tempdir");
 }