Build Makepad's catalog apps in the checkout, shared by every home

crates/shell/src/clients.rs

@@ -1098,6 +1098,12 @@ fn env_target_dir(dir: &Path) -> Option<PathBuf> {
     std::env::var_os("CARGO_TARGET_DIR").filter(|v| !v.is_empty()).map(|v| dir.join(v))
 }
 
+/// The target dir of the workspace at `root`, where its native apps build:
+/// `CARGO_TARGET_DIR` as cargo reads it there, else `<root>/target`.
+pub(crate) fn workspace_target_dir(root: &Path) -> PathBuf {
+    env_target_dir(root).unwrap_or_else(|| root.join("target"))
+}
+
 /// The launch of `app` (the release-only law: a hosted app is always a
 /// release build).
 ///
@@ -1131,7 +1137,7 @@ pub fn launch_plan(app: &AppDef, root: Option<&Path>, extra_args: &[String]) ->
             // The desktop package lives in the workspace (`desktop/`): build
             // from the workspace itself, where its lock and target dir are.
             let root = &workspace_root(root);
-            let target = env_target_dir(root).unwrap_or_else(|| root.join("target"));
+            let target = workspace_target_dir(root);
             (root.to_path_buf(), root.join("Cargo.toml"), package.to_string(), bin.to_string(), target, true, Some(PROCESS_APPS))
         }
         _ => {
@@ -1809,6 +1815,27 @@ mod tests {
         assert_eq!(build.dir, Path::new("/cargo/checkouts/makepad-d00a/ad8f372"), "cargo runs in its checkout");
     }
 
+    /// Makepad's apps build in the checkout's own target dir, beside the
+    /// native apps, never in the OctoSense home: a test or demo profile
+    /// opens them already built, where one under the home built all six
+    /// again, minutes each (20 Oct 2026).
+    #[test]
+    fn makepad_launches_share_the_checkouts_build_with_every_home() {
+        let apps = crate::octosense::catalog::parse_catalog(
+            br#"[{"id":"files","label":"Files","source":"makepad","package":"makepad-files","bin":"files"}]"#,
+            Path::new("/catalog"),
+            Some(Path::new("/checkout/.sources/makepad")),
+        )
+        .unwrap();
+        let root = repo_root().expect("the tests run in a checkout");
+        let build = launch_plan(&apps[0], Some(&root), &[]).unwrap().build.unwrap();
+        let native = AppDef::app("terminal", "Terminal", "makepad-terminal", "", "terminal", LaunchPolicy::AlwaysNew);
+        let native = launch_plan(&native, Some(&root), &[]).unwrap().build.unwrap();
+        assert_eq!(build.target_dir, native.target_dir.join("makepad"), "beside the native apps' builds");
+        assert!(!build.target_dir.starts_with(crate::octosense::paths::home()), "{}", build.target_dir.display());
+        assert!(build.args.windows(2).any(|p| p[0] == "--target-dir" && Path::new(&p[1]) == build.target_dir), "{:?}", build.args);
+    }
+
     #[test]
     fn installed_catalog_refreshes_without_shadowing_native_apps() {
         let app = |id: &str, label: &str| AppDef::app(id, label, "", "", "card", LaunchPolicy::OrFocus);

crates/shell/src/octosense/catalog.rs

@@ -74,13 +74,7 @@ pub fn parse_catalog(
                 let Some(root) = makepad_root else {
                     return Ok(None);
                 };
-                target_dir = Some(
-                    super::paths::home()
-                        .join("build")
-                        .join(name)
-                        .to_string_lossy()
-                        .into_owned(),
-                );
+                target_dir = Some(makepad_target_dir().to_string_lossy().into_owned());
                 (
                     Some(root.join("Cargo.toml").to_string_lossy().into_owned()),
                     required("package")?,
@@ -139,6 +133,19 @@ pub fn parse_catalog(
     Ok(out)
 }
 
+/// Where the catalog's Makepad rows build: `makepad/` in the checkout's own
+/// target dir, beside the native apps (`CARGO_TARGET_DIR` when set). Every
+/// OctoSense home run from the checkout, a test or demo profile too, shares
+/// that one build; under the home, each new profile built all six apps
+/// again, minutes each. With no checkout to find, the home's
+/// `build/makepad`.
+fn makepad_target_dir() -> PathBuf {
+    match super::paths::project_root() {
+        Some(project) => crate::clients::workspace_target_dir(&crate::clients::workspace_root(&project)).join("makepad"),
+        None => super::paths::home().join("build").join("makepad"),
+    }
+}
+
 fn catalog_path() -> Result<Option<PathBuf>, String> {
     let args: Vec<_> = std::env::args().collect();
     if let Some(i) = args.iter().position(|a| a == "--apps") {

crates/shell/src/sandbox/tests.rs

@@ -634,9 +634,11 @@ fn the_allow_list_never_admits_a_secret_shaped_name() {
 
 #[test]
 fn a_program_inside_the_octosense_home_stays_readable() {
-    // The desktop builds process apps into `<OctoSense home>/build`: the
-    // private deny must not take the app's own program away (the Terminal
-    // crashed at start, unable to read its own bundle).
+    // A process app's program can sit inside the OctoSense home (the
+    // desktop built Makepad's catalog apps into `<OctoSense home>/build`
+    // until they moved to the checkout's target dir): the private deny must
+    // not take the app's own program away (the Terminal crashed at start,
+    // unable to read its own bundle).
     let root = Path::new("/nonexistent/home");
     let mut p = home_rw_with_octosense_home(root);
     let build = root.join(".octosense/build/makepad");

desktop/README.md

@@ -319,7 +319,7 @@ Catalog lookup: `--apps <file>` if given, else `~/.octosense/apps.json` if it ex
 ]
 ```
 
-- `"source": "makepad"` resolves through Cargo to the same Makepad checkout as the host (`.sources/makepad`); such builds go to `~/.octosense/build/makepad`.
+- `"source": "makepad"` resolves through Cargo to the same Makepad checkout as the host (`.sources/makepad`); such builds go to the checkout's `target/makepad` (`$CARGO_TARGET_DIR/makepad` when set), beside the native apps, and every OctoSense home run from that checkout shares them. Older shells built them into `~/.octosense/build/makepad`; that folder is no longer used and can be deleted.
 - Step-by-step guides (Chinese): [open a hosted app](docs/open-apps.md), including the fix for an empty catalog when `cargo metadata --offline` fails, and [open the full Makepad catalog](docs/add-all-makepad-apps.md).
 - Relative paths resolve from the catalog's directory. Arguments are passed literally, without a shell.
 - `policy`: `"new"` opens another instance; `"focus"` (default) focuses a running one.

desktop/README.zh-CN.md

@@ -304,7 +304,7 @@ OCTOSENSE_HUB_CATALOG=legacy \
 ]
 ```
 
-- `"source": "makepad"` 通过 Cargo 解析到与宿主相同的 Makepad 检出（`.sources/makepad`）；这类构建输出到 `~/.octosense/build/makepad`。
+- `"source": "makepad"` 通过 Cargo 解析到与宿主相同的 Makepad 检出（`.sources/makepad`）；这类构建输出到该检出的 `target/makepad`（设置了 `CARGO_TARGET_DIR` 时为 `$CARGO_TARGET_DIR/makepad`），与原生应用的构建放在一起，从该检出运行的每个 OctoSense 主目录都共用它们。旧版 Shell 把它们构建到 `~/.octosense/build/makepad`；该目录已不再使用，可以删除。
 - 分步指南：[打开托管应用](docs/open-apps.md)（包括 `cargo metadata --offline` 失败导致目录为空时的修复方法），以及[打开完整的 Makepad 目录](docs/add-all-makepad-apps.md)。
 - 相对路径相对于目录文件所在目录解析。参数按原样传递，不经过 shell。
 - `policy`：`"new"` 打开新实例；`"focus"`（默认）聚焦已运行的实例。