debugger: Fix Rust debugger runnable (#28801)

We ran the locator after configuring the debugger binary which cause the
binary to never use the configuration from the cargo locator. This PR
fixes this by correcting the order of configuration.


co-authored-by Anthony Eid <anthony@zed.dev>

Release Notes:

- N/A

---------

Co-authored-by: piotr <piotr@zed.dev>

crates/project/src/debugger/dap_store.rs

@@ -21,7 +21,10 @@ use futures::{
     channel::{mpsc, oneshot},
     future::{Shared, join_all},
 };
-use gpui::{App, AppContext, AsyncApp, Context, Entity, EventEmitter, SharedString, Task};
+use gpui::{
+    App, AppContext, AsyncApp, BackgroundExecutor, Context, Entity, EventEmitter, SharedString,
+    Task,
+};
 use http_client::HttpClient;
 use language::{BinaryStatus, LanguageRegistry, LanguageToolchainStore};
 use lsp::LanguageServerName;
@@ -90,6 +93,17 @@ impl LocalDapStore {
     fn next_session_id(&self) -> SessionId {
         SessionId(self.next_session_id.fetch_add(1, SeqCst))
     }
+    pub(crate) fn locate_binary(
+        &self,
+        mut definition: DebugTaskDefinition,
+        executor: BackgroundExecutor,
+    ) -> Task<DebugTaskDefinition> {
+        let locator_store = self.locator_store.clone();
+        executor.spawn(async move {
+            let _ = locator_store.resolve_debug_config(&mut definition).await;
+            definition
+        })
+    }
 }
 
 pub struct RemoteDapStore {
@@ -335,7 +349,7 @@ impl DapStore {
     pub fn new_session(
         &mut self,
         binary: DebugAdapterBinary,
-        mut config: DebugTaskDefinition,
+        config: DebugTaskDefinition,
         parent_session: Option<Entity<Session>>,
         cx: &mut Context<Self>,
     ) -> (SessionId, Task<Result<Entity<Session>>>) {
@@ -352,22 +366,10 @@ impl DapStore {
         }
 
         let (initialized_tx, initialized_rx) = oneshot::channel();
-        let locator_store = local_store.locator_store.clone();
 
         let start_debugging_tx = local_store.start_debugging_tx.clone();
 
         let task = cx.spawn(async move |this, cx| {
-            if config.locator.is_some() {
-                config = cx
-                    .background_spawn(async move {
-                        locator_store
-                            .resolve_debug_config(&mut config)
-                            .await
-                            .map(|_| config)
-                    })
-                    .await?;
-            }
-
             let start_client_task = this.update(cx, |this, cx| {
                 Session::local(
                     this.breakpoint_store.clone(),

crates/project/src/debugger/locator_store/cargo.rs

@@ -1,13 +1,12 @@
 use super::DapLocator;
 use anyhow::{Result, anyhow};
 use async_trait::async_trait;
-use serde_json::{Value, json};
+use serde_json::Value;
 use smol::{
     io::AsyncReadExt,
     process::{Command, Stdio},
 };
 use task::DebugTaskDefinition;
-use util::maybe;
 
 pub(super) struct CargoLocator;
 
@@ -109,43 +108,13 @@ impl DapLocator for CargoLocator {
                 None
             }
         };
+
         let Some(executable) = executable.or_else(|| executables.first().cloned()) else {
             return Err(anyhow!("Couldn't get executable in cargo locator"));
         };
 
         launch_config.program = executable;
 
-        if debug_config.adapter == "LLDB" && debug_config.initialize_args.is_none() {
-            // Find Rust pretty-printers in current toolchain's sysroot
-            let cwd = launch_config.cwd.clone();
-            debug_config.initialize_args = maybe!(async move {
-                let cwd = cwd?;
-
-                let output = Command::new("rustc")
-                    .arg("--print")
-                    .arg("sysroot")
-                    .current_dir(cwd)
-                    .output()
-                    .await
-                    .ok()?;
-
-                if !output.status.success() {
-                    return None;
-                }
-
-                let sysroot_path = String::from_utf8(output.stdout).ok()?;
-                let sysroot_path = sysroot_path.trim_end();
-                let first_command = format!(
-                    r#"command script import "{sysroot_path}/lib/rustlib/etc/lldb_lookup.py"#
-                );
-                let second_command =
-                    format!(r#"command source -s 0 '{sysroot_path}/lib/rustlib/etc/lldb_commands"#);
-
-                Some(json!({"initCommands": [first_command, second_command]}))
-            })
-            .await;
-        }
-
         launch_config.args.clear();
         if let Some(test_name) = test_name {
             launch_config.args.push(test_name);

crates/project/src/project.rs

@@ -1482,6 +1482,18 @@ impl Project {
                     .update(cx, |dap_store, cx| dap_store.delegate(&worktree, cx))
             })?;
 
+            let task = this.update(cx, |project, cx| {
+                project.dap_store.read(cx).as_local().and_then(|local| {
+                    config.locator.is_some().then(|| {
+                        local.locate_binary(config.clone(), cx.background_executor().clone())
+                    })
+                })
+            })?;
+            let config = if let Some(task) = task {
+                task.await
+            } else {
+                config
+            };
             let binary = adapter
                 .get_binary(&delegate, &config, user_installed_path, cx)
                 .await?;