diff --git a/.github/workflows/run.yml b/.github/workflows/run.yml
index 413333f..78f9be6 100644
--- a/.github/workflows/run.yml
+++ b/.github/workflows/run.yml
@@ -49,6 +49,9 @@ jobs:
           chmod +x ~/.cargo/bin/os-checker
           os-checker layout --help
 
+      # - name: Test get_release_count
+      #   run: cargo test -- test_get_release_count --nocapture
+      #
       # - name: Test os-checker layout --list-targets
       #   run: cargo test -- test_sel4 --nocapture
       #
diff --git a/src/crates_io.rs b/src/crates_io.rs
new file mode 100644
index 0000000..8e89824
--- /dev/null
+++ b/src/crates_io.rs
@@ -0,0 +1,55 @@
+fn url(pkg: &str) -> String {
+    const PREFIX: &str =
+        "https://raw.githubusercontent.com/rust-lang/crates.io-index/refs/heads/master";
+
+    // ref: https://doc.rust-lang.org/cargo/reference/registry-index.html#index-files
+    let components = match pkg.len() {
+        1 => &["1", pkg][..],
+        2 => &["2", pkg],
+        3 => {
+            let (a, b) = pkg.split_at(1);
+            &["3", a, b, pkg]
+        }
+        _ => {
+            let (a, b) = pkg.split_at(2);
+            let (b, _) = b.split_at(2);
+            &[a, b, pkg]
+        }
+    };
+
+    // e.g. https://raw.githubusercontent.com/rust-lang/crates.io-index/refs/heads/master/os/-c/os-checker
+    let mut buf = String::with_capacity(128);
+    buf.push_str(PREFIX);
+
+    for c in components {
+        buf.push('/');
+        buf.push_str(c);
+    }
+
+    buf
+}
+
+/// NOTE: the result might be spurious due to network failure or invalid text;
+///
+/// None means no release found; 0 is an invalid value because there at least one
+/// release if found.
+pub fn get_release_count(pkg: &str) -> Option<usize> {
+    let url = url(pkg);
+    let output = duct::cmd!("wget", &url, "-O", "-")
+        .stdout_capture()
+        .stderr_null()
+        .run()
+        .ok()?;
+
+    let text = std::str::from_utf8(&output.stdout).ok()?.trim();
+    let count = text.lines().count();
+    if count == 0 {
+        error!(pkg, url, text, "count is an invalid value 0")
+    }
+    Some(count)
+}
+
+#[test]
+fn test_get_release_count() {
+    dbg!(get_release_count("os-checker"));
+}
diff --git a/src/lib.rs b/src/lib.rs
index b9cffb1..6715485 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,6 +11,7 @@ extern crate eyre;
 #[macro_use]
 extern crate tracing;
 
+pub mod crates_io;
 pub mod database;
 pub mod logger;
 pub mod nextest;
diff --git a/src/repo/mod.rs b/src/repo/mod.rs
index 08aed6c..2172cbd 100644
--- a/src/repo/mod.rs
+++ b/src/repo/mod.rs
@@ -1,4 +1,4 @@
-use crate::{database::diag_total_count, prelude::*};
+use crate::{crates_io::get_release_count, database::diag_total_count, prelude::*};
 use cargo_metadata::Package;
 use eyre::ContextCompat;
 use output::Output;
@@ -83,6 +83,7 @@ impl Repo {
             let pkg_name = pkg.name.as_str();
             let mut output = Output::new(pkg, test_cases.swap_remove(pkg_name));
             output.diag_total_count = diag_total_count([&self.user, &self.repo, pkg_name]);
+            output.release_count = get_release_count(pkg_name);
             assert!(
                 outputs.insert(pkg_name, output).is_none(),
                 "os-checker can't handle duplicated package names in a repo"
@@ -114,8 +115,13 @@ impl Repo {
 }
 
 pub fn local_base_dir() -> &'static Utf8Path {
-    static GIT_CLONE_DIR: LazyLock<Utf8PathBuf> =
-        LazyLock::new(|| Utf8PathBuf::from_iter(["/tmp", "os-checker-plugin-cargo"]));
+    static GIT_CLONE_DIR: LazyLock<Utf8PathBuf> = LazyLock::new(|| {
+        let path = Utf8PathBuf::from_iter(["/tmp", "os-checker-plugin-cargo"]);
+        if let Err(err) = std::fs::create_dir_all(&path) {
+            error!(?err, ?path, "directory is not created");
+        };
+        path
+    });
 
     &GIT_CLONE_DIR
 }
diff --git a/src/repo/output.rs b/src/repo/output.rs
index 04da7ac..f317bf0 100644
--- a/src/repo/output.rs
+++ b/src/repo/output.rs
@@ -21,6 +21,8 @@ pub struct Output {
     pub categories: Vec<String>,
     pub os_categories: Vec<String>,
     pub diag_total_count: Option<usize>,
+    /// crates.io 发版次数
+    pub release_count: Option<usize>,
 }
 
 impl Output {
@@ -55,6 +57,7 @@ impl Output {
                 })
                 .unwrap_or_default(),
             diag_total_count: None,
+            release_count: None,
         }
     }
 }