diff --git a/frontend/performance/benches/render_wasm/node/artifacts.cljs b/frontend/performance/benches/render_wasm/node/artifacts.cljs
index bb3b76df2a..870dc215b4 100644
--- a/frontend/performance/benches/render_wasm/node/artifacts.cljs
+++ b/frontend/performance/benches/render_wasm/node/artifacts.cljs
@@ -89,6 +89,12 @@
         (recur (path/dirname existing))))
     managed))
 
+(defn inside-builds?
+  "Checks the whole builds tree, resolving symlink ancestors of both paths."
+  [frontend-root output-path]
+  (contained? (files/get-real-path (path/join (managed-root frontend-root) "builds"))
+              (files/get-real-path output-path)))
+
 (defn- build-reference
   [root id manifest]
   (let [dir (path/join (managed-root root) "builds" id)]
@@ -210,31 +216,77 @@
                       {:type ::not-ready :id id :status (:status manifest)})))
     (check-files (assoc build :manifest manifest))))
 
+(def ^:private build-outputs
+  ["build.transit" "build.log" "cases.cjs" "index.html"
+   "browser/browser.js" "renderer/render-wasm.js" "renderer/render-wasm.wasm"
+   "renderer/render-wasm.wasm.map" "renderer/shared.js" "renderer/cargo-build.json"
+   "renderer/worker/render.js"])
+
+(defn- directory?
+  [file]
+  (and (fs/existsSync file) (.isDirectory (fs/statSync file))))
+
+(defn- unlink-if-present
+  [file]
+  (when-not (directory? file)
+    (try
+      (fs/unlinkSync file)
+      (catch :default error
+        (when-not (contains? #{"ENOENT" "ENOTDIR"} (.-code error))
+          (throw error))))))
+
+(defn- clean-build
+  [dir]
+  (when (directory? dir)
+    (doseq [file build-outputs]
+      (unlink-if-present (path/join dir file)))))
+
+(defn- purge-builds
+  [root]
+  (when (directory? root)
+    (doseq [id (array-seq (fs/readdirSync root))]
+      (clean-build (path/join root id)))))
+
+(defn- purge-runs
+  [root]
+  (loop [pending [root]
+         visited #{}]
+    (when-let [dir (peek pending)]
+      (let [pending (pop pending)
+            real    (when (directory? dir) (fs/realpathSync dir))]
+        (if (or (nil? real) (contains? visited real))
+          (recur pending visited)
+          (do
+            (unlink-if-present (path/join dir "run.log"))
+            (let [names (array-seq (fs/readdirSync dir))]
+              (doseq [file names
+                      :when (str/ends-with? (str/lower-case file) ".png")]
+                (unlink-if-present (path/join dir file)))
+              (unlink-if-present (path/join dir "run.transit"))
+              (recur (into pending (map #(path/join dir %) names))
+                     (conj visited real)))))))))
+
 (defn purge
-  "Deletes :builds, :runs or both (:all), including unfinished builds.
+  "Unlinks known outputs from :builds, :runs or both (:all).
 
   The caller must be idle: no build, server or run may still own these paths.
-  Boot executables and other files beside the managed subroots stay in place.
-  A selected subroot symlink is removed without deleting its target."
+  Follows directory symlinks; keeps directories and unrelated files."
   [root category]
   (let [managed (managed-root root)]
     (case category
-      :builds (fs/rmSync (path/join managed "builds") #js {:recursive true :force true})
-      :runs (fs/rmSync (path/join managed "runs") #js {:recursive true :force true})
+      :builds (purge-builds (path/join managed "builds"))
+      :runs (purge-runs (path/join managed "runs"))
       :all (do
-             (fs/rmSync (path/join managed "builds") #js {:recursive true :force true})
-             (fs/rmSync (path/join managed "runs") #js {:recursive true :force true}))
+             (purge-builds (path/join managed "builds"))
+             (purge-runs (path/join managed "runs")))
       (throw (ex-info "invalid renderer artifact category"
                       {:type ::invalid-category :category category})))))
 
 (defn remove-builds
-  "Deletes only the selected build IDs. The caller must be idle."
+  "Unlinks known outputs of selected build IDs. The caller must be idle."
   [root ids]
   (let [ids     (mapv check-id ids)
         managed (managed-root root)
         builds  (path/join managed "builds")]
-    (when (fs/existsSync builds)
-      (checked-path (fs/realpathSync managed) builds)
-      (doseq [id ids]
-        ;; rmSync removes a final symlink itself, not its target.
-        (fs/rmSync (path/join builds id) #js {:recursive true :force true})))))
+    (doseq [id ids]
+      (clean-build (path/join builds id)))))
diff --git a/frontend/performance/benches/render_wasm/node/files.cljs b/frontend/performance/benches/render_wasm/node/files.cljs
index d4e006bc5b..d6a9ebe26e 100644
--- a/frontend/performance/benches/render_wasm/node/files.cljs
+++ b/frontend/performance/benches/render_wasm/node/files.cljs
@@ -7,7 +7,16 @@
 (ns benches.render-wasm.node.files
   "Small filesystem helpers shared by benchmark storage writers."
   (:require
-   ["fs" :as fs]))
+   ["fs" :as fs]
+   ["path" :as path]))
+
+(defn get-real-path
+  "Resolves symlink ancestors even when the final path does not exist yet."
+  [file]
+  (let [file (path/resolve file)]
+    (if (fs/existsSync file)
+      (fs/realpathSync file)
+      (path/join (get-real-path (path/dirname file)) (path/basename file)))))
 
 (defn atomic-write
   "Writes (UTF-8) content to a temporary file and renames it over `file`,
diff --git a/frontend/performance/benches/render_wasm/node/run.cljs b/frontend/performance/benches/render_wasm/node/run.cljs
index c5df581063..e65e8978fb 100644
--- a/frontend/performance/benches/render_wasm/node/run.cljs
+++ b/frontend/performance/benches/render_wasm/node/run.cljs
@@ -646,18 +646,14 @@
       (dissoc :screenshots :remove)))
 
 (defn ^:async execute
-  "Executes a prepared selection and owns the run home, host and browser.
+  "Executes a prepared selection in an allocated home and owns host and browser.
 
   Options are resolved CLI options. root is the frontend checkout. The record
   exists before on-created runs, so a browser startup failure still leaves a
   valid partial record. Returns {:run RunRecord :home home :exit-code n
   :error cause-or-nil}."
-  [root selected-build cases options signal on-progress on-created]
-  (let [opts  (-> (normalize-options options)
-                  (assoc :run-id (or (:run-id options) (str (random-uuid)))))
-        home  (runs/create-home {:root root
-                                 :run-id (:run-id opts)
-                                 :output-dir (:output-dir opts)})
+  [root home selected-build cases options signal on-progress on-created]
+  (let [opts  (assoc (normalize-options options) :run-id (:run-id home))
         run   (result/create-run
                {:run-id (:run-id opts)
                 :started-at (now)
@@ -748,13 +744,13 @@
 (defn ^:async run
   "Prepares or loads a build, collects matching cases and executes one run.
 
-  User output paths resolve before any build work. A build or catalog failure
-  before the plan exists creates no run record and rethrows with build facts."
+  The output home is reserved before build work so filesystem errors fail fast.
+  A build or catalog failure leaves the home without a run record and rethrows
+  with build facts."
   [root options signal on-progress on-created]
-  (let [opts       (normalize-options options)
-        output-dir (runs/check-output-dir (:output-dir opts))
-        run-id     (str (random-uuid))
-        opts       (assoc opts :run-id run-id :output-dir output-dir)]
+  (let [opts (normalize-options options)
+        home (runs/create-home {:root root :run-id (str (random-uuid))
+                                :output-dir (:output-dir opts) :remove (:remove? opts)})]
     (try
       (let [selected-build
             (if-let [id (:build-id opts)]
@@ -779,7 +775,7 @@
                                              :build-id (:id selected-build)
                                              :log-path (:log-path selected-build))
                                       cause))))]
-        (await (execute root selected-build cases opts signal on-progress on-created)))
+        (await (execute root home selected-build cases opts signal on-progress on-created)))
       (catch :default cause
         (when on-progress
           (on-progress (str "run: " (message-of cause) "\n"))
diff --git a/frontend/performance/benches/render_wasm/node/runs.cljs b/frontend/performance/benches/render_wasm/node/runs.cljs
index 00480a1852..dfce353b1a 100644
--- a/frontend/performance/benches/render_wasm/node/runs.cljs
+++ b/frontend/performance/benches/render_wasm/node/runs.cljs
@@ -9,8 +9,8 @@
 
   Runs are saved under <frontend>/target/performance/render-wasm/runs.
 
-  This can be overriden in the runner with `--output-dir PATH`. If done, this
-  path is not included among those purged when cleaning up."
+  --output-dir selects another destination. Purge cleans files reachable from
+  the default runs tree, including explicit destinations and directory links."
   (:require
    ["fs" :as fs]
    ["path" :as path]
@@ -37,7 +37,7 @@
     (when (str/blank? dir)
       (invalid-home "output directory requires a nonempty path" {}))
     (let [resolved (path/resolve dir)]
-      (when (fs/existsSync resolved)
+      (when (fs/lstatSync resolved #js {:throwIfNoEntry false})
         (invalid-home "output directory already exists" {:path resolved}))
       resolved)))
 
@@ -45,18 +45,16 @@
   "Creates one run home and its empty log. The record is written separately
   after the plan exists. An explicit directory must not exist; a managed home
   uses the frontend root regardless of cwd."
-  [{:keys [root run-id output-dir]}]
+  [{:keys [root run-id output-dir remove]}]
   (check-id run-id)
-  (let [explicit   (check-output-dir output-dir)
-        managed    (when-not explicit (artifacts/managed-root root))
-        runs-dir   (when managed (path/join managed "runs"))
-        dir        (or explicit (path/join runs-dir run-id))
+  (let [dir        (check-output-dir
+                    (or output-dir (path/join (artifacts/managed-root root) "runs" run-id)))
         record-path (path/join dir "run.transit")
         log-path    (path/join dir "run.log")]
-    (when managed
-      (fs/mkdirSync runs-dir #js {:recursive true}))
+    (when (and remove (artifacts/inside-builds? root dir))
+      (invalid-home "--remove cannot use an output directory inside builds" {:path dir}))
     (try
-      (fs/mkdirSync dir)
+      (fs/mkdirSync dir #js {:recursive true})
       (catch :default cause
         (invalid-home "cannot create run home"
                       {:path dir :cause (or (ex-message cause) (str cause))})))
diff --git a/frontend/test/performance_tests/render_wasm/artifacts_test.cljs b/frontend/test/performance_tests/render_wasm/artifacts_test.cljs
index 98e2a22321..39fb7da204 100644
--- a/frontend/test/performance_tests/render_wasm/artifacts_test.cljs
+++ b/frontend/test/performance_tests/render_wasm/artifacts_test.cljs
@@ -257,38 +257,74 @@
     (t/is (= ::artifacts/unsafe-path
              (:type (ex-data (failure #(artifacts/load-build @temporary-root (:id build)))))))))
 
-(t/deftest category-purge-deletes-only-the-requested-managed-subroots
+(t/deftest category-purge-unlinks-only-known-outputs-and-keeps-directories
   (doseq [category [:builds :runs :all]]
     (let [root     (fs/mkdtempSync (path/join @temporary-root (str (name category) "-")))
-          building (artifacts/create-build root selection provenance)
+          building (complete-files (artifacts/create-build root selection provenance))
           failed   (artifacts/create-build root selection provenance)
           managed  (artifacts/managed-root root)
-          run-file (path/join managed "runs" "saved-run" "record.transit")
+          run-dir  (path/join managed "runs" "group" "saved-run")
+          outputs  ["build.transit" "build.log" "cases.cjs" "index.html"
+                    "browser/browser.js" "renderer/render-wasm.js"
+                    "renderer/render-wasm.wasm" "renderer/render-wasm.wasm.map"
+                    "renderer/shared.js" "renderer/cargo-build.json"
+                    "renderer/worker/render.js"]
           boot     (path/join managed "runner.cjs")
-          outside  (path/join root "unmanaged.txt")]
+          outside  (path/join root "explicit-output" "run.transit")]
       (artifacts/write-manifest failed (assoc (:manifest failed) :status :failed))
-      (write-file run-file "retained run")
+      (doseq [file outputs]
+        (write-file (path/join (:dir building) file) "build output"))
+      (doseq [file ["run.log" "run.transit" "shot.png" "SHOT.PNG"]]
+        (write-file (path/join run-dir file) "run output"))
+      (doseq [dir ["run.log" "run.transit" "directory.PNG"]]
+        (write-file (path/join managed "runs" dir "keep.txt") "keep directory"))
+      (write-file (path/join managed "runs" "no-marker" "only.PNG") "screenshot")
+      (write-file (path/join run-dir "record.transit") "unrelated run file")
+      (write-file (path/join (:dir building) "custom" "build.log") "unrelated build file")
       (write-file boot "boot executable")
       (write-file outside "unmanaged")
       (artifacts/purge root category)
-      (t/is (= (= category :runs) (fs/existsSync (:dir building))))
-      (t/is (= (= category :runs) (fs/existsSync (:dir failed))))
-      (t/is (= (= category :builds) (fs/existsSync run-file)))
+      (doseq [dir [(:dir building) (:dir failed) (:browser-dir building)
+                   (:renderer-dir building) run-dir]]
+        (t/is (.isDirectory (fs/statSync dir))))
+      (doseq [file outputs]
+        (t/is (= (= category :runs) (fs/existsSync (path/join (:dir building) file)))))
+      (t/is (= (= category :runs) (fs/existsSync (:manifest-path failed))))
+      (doseq [file ["run.log" "run.transit" "shot.png" "SHOT.PNG"]]
+        (t/is (= (= category :builds) (fs/existsSync (path/join run-dir file)))))
+      (t/is (= (= category :builds)
+               (fs/existsSync (path/join managed "runs" "no-marker" "only.PNG"))))
+      (doseq [dir ["run.log" "run.transit" "directory.PNG"]]
+        (t/is (fs/existsSync (path/join managed "runs" dir "keep.txt"))))
+      (t/is (fs/existsSync (path/join run-dir "record.transit")))
+      (t/is (fs/existsSync (path/join (:dir building) "custom" "build.log")))
       (t/is (= "boot executable" (fs/readFileSync boot "utf8")))
       (t/is (= "unmanaged" (fs/readFileSync outside "utf8")))
       (artifacts/purge root category))))
 
-(t/deftest purge-removes-selected-subroot-symlinks-without-deleting-their-targets
+(t/deftest purge-follows-category-and-nested-directory-symlinks-and-stops-cycles
   (let [managed (artifacts/managed-root @temporary-root)]
     (fs/mkdirSync managed #js {:recursive true})
     (doseq [category [:builds :runs]]
       (let [outside (path/join @temporary-root (str "outside-" (name category)))
+            detached (path/join @temporary-root (str "detached-" (name category)))
+            output  (if (= category :builds) "build.transit" "run.transit")
             saved   (path/join outside "keep.txt")
             link    (path/join managed (name category))]
         (write-file saved "keep symlink target")
+        (write-file (path/join outside "saved" output) "output, not a parsed record")
+        (write-file (path/join detached output) "linked output")
+        (write-file (path/join detached "keep.txt") "unrelated")
+        (fs/symlinkSync outside (path/join outside "saved" "cycle") "dir")
+        (fs/symlinkSync detached (path/join outside "linked") "dir")
         (fs/symlinkSync outside link "dir")
         (artifacts/purge @temporary-root category)
-        (t/is (not (fs/existsSync link)))
+        (t/is (.isSymbolicLink (fs/lstatSync link)))
+        (t/is (.isSymbolicLink (fs/lstatSync (path/join outside "saved" "cycle"))))
+        (t/is (.isSymbolicLink (fs/lstatSync (path/join outside "linked"))))
+        (t/is (not (fs/existsSync (path/join outside "saved" output))))
+        (t/is (not (fs/existsSync (path/join detached output))))
+        (t/is (fs/existsSync (path/join detached "keep.txt")))
         (t/is (= "keep symlink target" (fs/readFileSync saved "utf8")))))))
 
 (t/deftest managed-root-symlink-cannot-create-or-delete-outside-the-frontend
@@ -336,23 +372,51 @@
     (t/is (= "keep external build" (fs/readFileSync saved "utf8")))
     (t/is (= #{"retained"} (set (array-seq (fs/readdirSync outside)))))))
 
-(t/deftest remove-builds-keeps-other-builds-runs-and-symlink-targets
-  (let [removed (create-build)
+(t/deftest remove-builds-cleans-selected-ids-and-keeps-directories-and-unrelated-files
+  (let [removed (ready-build)
         kept    (ready-build)
         managed (artifacts/managed-root @temporary-root)
-        run     (path/join managed "runs" "saved" "record.transit")
+        run     (path/join managed "runs" "saved" "run.transit")
         outside (path/join @temporary-root "outside" "keep.txt")
+        browser (path/join @temporary-root "linked-browser")
         link    (path/join managed "builds" "outside-link")]
     (write-file run "keep run")
     (write-file outside "keep target")
+    (write-file (path/join (:dir removed) "screenshot.PNG") "keep build screenshot")
+    (write-file (path/join (path/dirname outside) "build.transit") "linked build output")
+    (write-file (path/join browser "browser.js") "linked browser output")
+    (write-file (path/join browser "keep.js") "unrelated")
+    (fs/symlinkSync browser (path/join (path/dirname outside) "browser") "dir")
     (fs/symlinkSync (path/dirname outside) link "dir")
     (artifacts/remove-builds @temporary-root [(:id removed) "outside-link" "absent-build"])
-    (t/is (not (fs/existsSync (:dir removed))))
-    (t/is (not (fs/existsSync link)))
+    (t/is (.isDirectory (fs/statSync (:dir removed))))
+    (t/is (not (fs/existsSync (:manifest-path removed))))
+    (t/is (not (fs/existsSync (:cases-path removed))))
+    (t/is (fs/existsSync (path/join (:dir removed) "screenshot.PNG")))
+    (t/is (.isSymbolicLink (fs/lstatSync link)))
+    (t/is (not (fs/existsSync (path/join link "build.transit"))))
+    (t/is (not (fs/existsSync (path/join browser "browser.js"))))
+    (t/is (fs/existsSync (path/join browser "keep.js")))
     (t/is (= kept (artifacts/load-build @temporary-root (:id kept))))
     (t/is (= "keep run" (fs/readFileSync run "utf8")))
     (t/is (= "keep target" (fs/readFileSync outside "utf8")))))
 
+(t/deftest inside-builds-resolves-symlink-ancestors-with-missing-output-components
+  (let [managed (artifacts/managed-root @temporary-root)
+        builds  (path/join managed "builds")
+        outside (path/join @temporary-root "external-builds")
+        alias   (path/join @temporary-root "build-alias")]
+    (t/is (artifacts/inside-builds? @temporary-root (path/join builds "future" "run")))
+    (fs/mkdirSync managed #js {:recursive true})
+    (fs/mkdirSync outside)
+    (fs/symlinkSync outside builds "dir")
+    (fs/symlinkSync builds alias "dir")
+    (doseq [output [builds outside (path/join builds "new" "run")
+                    (path/join outside "new" "run") (path/join alias "new" "run")]]
+      (t/is (artifacts/inside-builds? @temporary-root output)))
+    (t/is (not (artifacts/inside-builds? @temporary-root (str outside "-neighbor/run"))))
+    (t/is (not (artifacts/inside-builds? @temporary-root (path/join managed "runs" "new"))))))
+
 (defn- descriptor
   [id]
   {:id id
diff --git a/frontend/test/performance_tests/render_wasm/cli_integration.cjs b/frontend/test/performance_tests/render_wasm/cli_integration.cjs
index 3eed938318..f8c204ba78 100644
--- a/frontend/test/performance_tests/render_wasm/cli_integration.cjs
+++ b/frontend/test/performance_tests/render_wasm/cli_integration.cjs
@@ -162,6 +162,7 @@ function seedBuilds(fixture) {
       manifestText(id, status, "renderer-build"),
     );
     fs.writeFileSync(path.join(directory, "build.log"), `${status} build\n`);
+    fs.writeFileSync(path.join(directory, "keep.txt"), "keep\n");
   }
 }
 
@@ -174,6 +175,9 @@ function seedRuns(fixture) {
       path.join(directory, "run.transit"),
       manifestText(id, status, "renderer-run"),
     );
+    fs.writeFileSync(path.join(directory, "run.log"), "run\n");
+    fs.writeFileSync(path.join(directory, "case-load.PNG"), "screenshot\n");
+    fs.writeFileSync(path.join(directory, "keep.txt"), "keep\n");
   }
 }
 
@@ -399,10 +403,16 @@ test("purge deletes only the selected artifacts", testOptions, async (t) => {
     stdout: "",
     stderr: "",
   });
-  assert.equal(fs.existsSync(fixture.builds), false);
+  for (const id of fs.readdirSync(fixture.builds)) {
+    assert.deepEqual(fs.readdirSync(path.join(fixture.builds, id)), [
+      "keep.txt",
+    ]);
+  }
   assert.deepEqual(tree(fixture.runs), runs);
   assert.deepEqual(
-    tree(fixture.managed).filter(([name]) => name !== "runs"),
+    tree(fixture.managed).filter(
+      ([name]) => !["runs", "builds"].includes(name),
+    ),
     retained,
   );
 
@@ -413,10 +423,14 @@ test("purge deletes only the selected artifacts", testOptions, async (t) => {
     stdout: "",
     stderr: "",
   });
-  assert.equal(fs.existsSync(fixture.runs), false);
+  for (const id of fs.readdirSync(fixture.runs)) {
+    assert.deepEqual(fs.readdirSync(path.join(fixture.runs, id)), ["keep.txt"]);
+  }
   assert.deepEqual(tree(fixture.builds), builds);
   assert.deepEqual(
-    tree(fixture.managed).filter(([name]) => name !== "builds"),
+    tree(fixture.managed).filter(
+      ([name]) => !["runs", "builds"].includes(name),
+    ),
     retained,
   );
 
@@ -426,11 +440,110 @@ test("purge deletes only the selected artifacts", testOptions, async (t) => {
     stdout: "",
     stderr: "",
   });
-  assert.equal(fs.existsSync(fixture.builds), false);
-  assert.equal(fs.existsSync(fixture.runs), false);
-  assert.deepEqual(tree(fixture.managed), retained);
+  for (const root of [fixture.builds, fixture.runs]) {
+    for (const id of fs.readdirSync(root)) {
+      assert.deepEqual(fs.readdirSync(path.join(root, id)), ["keep.txt"]);
+    }
+  }
+  assert.deepEqual(
+    tree(fixture.managed).filter(
+      ([name]) => !["runs", "builds"].includes(name),
+    ),
+    retained,
+  );
 });
 
+test(
+  "run reserves nested output before the compiler starts",
+  testOptions,
+  async (t) => {
+    const fixture = createFrontend(t);
+    const output = path.join(fixture.managed, "missing", "parents", "output");
+    const marker = path.join(fixture.managed, "compiler-ran");
+    fs.writeFileSync(
+      fixture.compiler,
+      `#!/usr/bin/env node
+const fs = require("node:fs");
+if (!fs.statSync(${JSON.stringify(path.join(output, "run.log"))}).isFile()) process.exit(99);
+fs.writeFileSync(${JSON.stringify(marker)}, "reserved");
+process.exit(23);
+`,
+      { mode: 0o755 },
+    );
+
+    const result = await runCli(fixture, ["run", "--output-dir", output]);
+
+    assert.equal(result.exitCode, 1);
+    assert.equal(result.stdout, "");
+    assert.equal(fs.readFileSync(marker, "utf8"), "reserved");
+    assert.equal(fs.existsSync(path.join(output, "run.transit")), false);
+  },
+);
+
+test(
+  "run rejects invalid output parents before invoking the compiler",
+  testOptions,
+  async (t) => {
+    const fixture = createFrontend(t);
+    const parent = path.join(fixture.managed, "not-a-directory");
+    const marker = path.join(fixture.managed, "compiler-ran");
+    fs.writeFileSync(parent, "keep");
+    fs.writeFileSync(
+      fixture.compiler,
+      `#!/usr/bin/env node
+require("node:fs").writeFileSync(${JSON.stringify(marker)}, "ran");
+process.exit(23);
+`,
+      { mode: 0o755 },
+    );
+
+    const result = await runCli(fixture, [
+      "run",
+      "--output-dir",
+      path.join(parent, "output"),
+    ]);
+
+    assert.equal(result.exitCode, 1);
+    assert.match(result.stderr, /ENOTDIR|cannot create run home/);
+    assert.equal(fs.existsSync(marker), false);
+    assert.equal(fs.readFileSync(parent, "utf8"), "keep");
+  },
+);
+
+test(
+  "run rejects --remove outputs inside builds including directory aliases",
+  testOptions,
+  async (t) => {
+    const fixture = createFrontend(t);
+    const marker = path.join(fixture.managed, "compiler-ran");
+    const alias = path.join(path.dirname(fixture.managed), "build-alias");
+    fs.mkdirSync(fixture.builds);
+    fs.symlinkSync(fixture.builds, alias, "dir");
+    fs.writeFileSync(
+      fixture.compiler,
+      `#!/usr/bin/env node
+require("node:fs").writeFileSync(${JSON.stringify(marker)}, "ran");
+process.exit(23);
+`,
+      { mode: 0o755 },
+    );
+
+    for (const root of [fixture.builds, alias]) {
+      const output = path.join(root, "missing", "output");
+      const result = await runCli(fixture, [
+        "run",
+        "--remove",
+        "--output-dir",
+        output,
+      ]);
+      assert.equal(result.exitCode, 1);
+      assert.match(result.stderr, /--remove.*inside builds/);
+      assert.equal(fs.existsSync(output), false);
+    }
+    assert.equal(fs.existsSync(marker), false);
+  },
+);
+
 test(
   "malformed purge categories leave all files intact",
   testOptions,
diff --git a/frontend/test/performance_tests/render_wasm/run_test.cljs b/frontend/test/performance_tests/render_wasm/run_test.cljs
index cac383c18f..995ec62171 100644
--- a/frontend/test/performance_tests/render_wasm/run_test.cljs
+++ b/frontend/test/performance_tests/render_wasm/run_test.cljs
@@ -12,6 +12,7 @@
    [app.common.transit :as transit]
    [benches.render-wasm.node.artifacts :as artifacts]
    [benches.render-wasm.node.run :as run]
+   [benches.render-wasm.node.runs :as runs]
    [benches.render-wasm.result :as result]
    [cljs.test :as t :include-macros true]
    [clojure.string :as str]))
@@ -181,6 +182,8 @@
    (execute fake cases opts (js/AbortController.)))
   ([_fake cases opts controller]
    (run/execute (artifacts/frontend-root)
+                (runs/create-home {:root (artifacts/frontend-root) :run-id (:run-id opts)
+                                   :output-dir (:output-dir opts)})
                 (selected-build (build-dir) "test-build")
                 cases opts (.-signal controller) nil nil)))
 
@@ -460,12 +463,15 @@
         _      (fs/writeFileSync (path/join dir "index.html") "<!doctype html>")
         fake   (fake-browser {})
         out    (path/join @temporary-root "remove-run")
-        result (await (run/execute root (selected-build dir id)
+        home   (runs/create-home {:root root :run-id "remove-run"
+                                  :output-dir out :remove true})
+        result (await (run/execute root home (selected-build dir id)
                                    [(collected :case/a :fresh)]
                                    (assoc (options fake out) :remove? true)
                                    (.-signal (js/AbortController.)) nil nil))]
     (t/is (fs/existsSync (get-in result [:home :record-path])))
-    (t/is (not (fs/existsSync dir)))
+    (t/is (fs/existsSync dir))
+    (t/is (not (fs/existsSync (path/join dir "index.html"))))
     (t/is (= :completed (get-in result [:run :termination :reason])))
     (t/is (zero? (:exit-code result)))))
 
@@ -488,7 +494,9 @@
                                    ;; attempts have reached the saved record.
                                    (fs/renameSync record prior)
                                    (fs/mkdirSync record))))
-        response   (await (run/execute root (selected-build dir id)
+        home       (runs/create-home {:root root :run-id "failed-write"
+                                      :output-dir out :remove true})
+        response   (await (run/execute root home (selected-build dir id)
                                        [(collected :case/a :fresh)]
                                        (assoc (options fake out) :remove true)
                                        (.-signal (js/AbortController.)) nil nil))
@@ -498,4 +506,5 @@
     (t/is (every? zero? (vals (get-in saved [:remaining :case/a]))))
     (t/is (some? (:error response)))
     (t/is (= 1 (:exit-code response)))
-    (t/is (fs/existsSync dir))))
+    (t/is (= "<!doctype html>"
+             (fs/readFileSync (path/join dir "index.html") "utf8")))))
diff --git a/frontend/test/performance_tests/render_wasm/runs_test.cljs b/frontend/test/performance_tests/render_wasm/runs_test.cljs
index 201c7a29f9..044d2c0b07 100644
--- a/frontend/test/performance_tests/render_wasm/runs_test.cljs
+++ b/frontend/test/performance_tests/render_wasm/runs_test.cljs
@@ -102,3 +102,29 @@
                             (runs/create-home {:root @temporary-root :run-id id}))))
   (t/is (thrown-with-msg? js/Error #"nonempty path"
                           (runs/check-output-dir "  "))))
+
+(t/deftest explicit-home-creates-missing-parents
+  (let [out  (path/join @temporary-root "missing" "parents" "run")
+        home (runs/create-home {:root @temporary-root :run-id "nested"
+                                :output-dir out})]
+    (t/is (.isDirectory (fs/statSync out)))
+    (t/is (= "" (fs/readFileSync (:log-path home) "utf8")))
+    (t/is (thrown-with-msg? js/Error #"already exists"
+                            (runs/create-home {:root @temporary-root :run-id "again"
+                                               :output-dir out})))))
+
+(t/deftest remove-rejects-output-inside-builds-before-creating-it
+  (let [builds (path/join (artifacts/managed-root @temporary-root) "builds")
+        alias  (path/join @temporary-root "build-alias")]
+    (fs/mkdirSync builds #js {:recursive true})
+    (fs/symlinkSync builds alias "dir")
+    (doseq [out [(path/join builds "direct")
+                 (path/join alias "missing" "nested")]]
+      (t/is (thrown-with-msg? js/Error #"--remove.*inside builds"
+                              (runs/create-home {:root @temporary-root :run-id "blocked"
+                                                 :output-dir out :remove true})))
+      (t/is (not (fs/existsSync out))))
+    (let [out (path/join @temporary-root "builds-other" "allowed")]
+      (runs/create-home {:root @temporary-root :run-id "allowed"
+                         :output-dir out :remove true})
+      (t/is (fs/existsSync (path/join out "run.log"))))))