Shell out to real tar in extension builder (#41856)

We see `test_extension_store_with_test_extension` hang in untarring the
WASI SDK some times.

In lieu of trying to debug the problem, let's try shelling out for now
in the hope that the test becomes more reliable.

There's a bit of risk here because we're using async-tar for other
things (but probably not 300Mb tar files...)

Assisted-By: Zed AI

Closes #ISSUE

Release Notes:

- N/A

Cargo.lock

@@ -5837,8 +5837,6 @@ name = "extension"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "async-compression",
- "async-tar",
  "async-trait",
  "collections",
  "dap",

crates/extension/Cargo.toml

@@ -13,8 +13,6 @@ path = "src/extension.rs"
 
 [dependencies]
 anyhow.workspace = true
-async-compression.workspace = true
-async-tar.workspace = true
 async-trait.workspace = true
 collections.workspace = true
 dap.workspace = true

crates/extension/src/extension_builder.rs

@@ -3,9 +3,7 @@ use crate::{
     parse_wasm_extension_version,
 };
 use anyhow::{Context as _, Result, bail};
-use async_compression::futures::bufread::GzipDecoder;
-use async_tar::Archive;
-use futures::{AsyncReadExt, io::Cursor};
+use futures::AsyncReadExt;
 use heck::ToSnakeCase;
 use http_client::{self, AsyncBody, HttpClient};
 use serde::Deserialize;
@@ -417,28 +415,48 @@ impl ExtensionBuilder {
             return Ok(clang_path);
         }
 
-        let mut tar_out_dir = wasi_sdk_dir.clone();
-        tar_out_dir.set_extension("archive");
+        let tar_out_dir = self.cache_dir.join("wasi-sdk-temp");
 
         fs::remove_dir_all(&wasi_sdk_dir).ok();
         fs::remove_dir_all(&tar_out_dir).ok();
+        fs::create_dir_all(&tar_out_dir).context("failed to create extraction directory")?;
 
-        log::info!("downloading wasi-sdk to {}", wasi_sdk_dir.display());
         let mut response = self.http.get(&url, AsyncBody::default(), true).await?;
-        let body = GzipDecoder::new({
-            // stream the entire request into memory at once as the artifact is quite big (100MB+)
-            let mut b = vec![];
-            response.body_mut().read_to_end(&mut b).await?;
-            Cursor::new(b)
-        });
-        let tar = Archive::new(body);
 
-        log::info!("un-tarring wasi-sdk to {}", wasi_sdk_dir.display());
-        tar.unpack(&tar_out_dir)
+        // Write the response to a temporary file
+        let tar_gz_path = self.cache_dir.join("wasi-sdk.tar.gz");
+        let mut tar_gz_file =
+            fs::File::create(&tar_gz_path).context("failed to create temporary tar.gz file")?;
+        let response_body = response.body_mut();
+        let mut body_bytes = Vec::new();
+        response_body.read_to_end(&mut body_bytes).await?;
+        std::io::Write::write_all(&mut tar_gz_file, &body_bytes)?;
+        drop(tar_gz_file);
+
+        log::info!("un-tarring wasi-sdk to {}", tar_out_dir.display());
+
+        // Shell out to tar to extract the archive
+        let tar_output = util::command::new_smol_command("tar")
+            .arg("-xzf")
+            .arg(&tar_gz_path)
+            .arg("-C")
+            .arg(&tar_out_dir)
+            .output()
             .await
-            .context("failed to unpack wasi-sdk archive")?;
+            .context("failed to run tar")?;
+
+        if !tar_output.status.success() {
+            bail!(
+                "failed to extract wasi-sdk archive: {}",
+                String::from_utf8_lossy(&tar_output.stderr)
+            );
+        }
+
         log::info!("finished downloading wasi-sdk");
 
+        // Clean up the temporary tar.gz file
+        fs::remove_file(&tar_gz_path).ok();
+
         let inner_dir = fs::read_dir(&tar_out_dir)?
             .next()
             .context("no content")?