diff --git a/studio/src-tauri/src/install.rs b/studio/src-tauri/src/install.rs
index 74e560a921..bdefca22a1 100644
--- a/studio/src-tauri/src/install.rs
+++ b/studio/src-tauri/src/install.rs
@@ -54,12 +54,29 @@ pub(crate) fn managed_install_in_progress() -> bool {
         .unwrap_or(false)
 }
 
+/// Whether this process created the marker rather than finding one an earlier
+/// interrupted install left. Clearing someone else's drops the only signal that
+/// its venv is half-written. Process-wide because the marker is one file.
+static MARKER_CREATED_HERE: std::sync::atomic::AtomicBool =
+    std::sync::atomic::AtomicBool::new(false);
+
 fn create_install_in_progress_marker() -> Result<(), String> {
     let path = install_in_progress_marker_path()?;
-    create_install_in_progress_marker_at(&path)
+    let created = create_install_in_progress_marker_at(&path)?;
+    MARKER_CREATED_HERE.store(created, std::sync::atomic::Ordering::Relaxed);
+    Ok(())
 }
 
-fn create_install_in_progress_marker_at(path: &Path) -> Result<(), String> {
+/// Clear only a marker this attempt created. Used where the venv was never
+/// touched: a failed spawn, and the elevation exits.
+fn clear_own_install_marker() {
+    if MARKER_CREATED_HERE.load(std::sync::atomic::Ordering::Relaxed) {
+        clear_install_marker_best_effort();
+    }
+}
+
+/// Ok(true) when this call created the file, Ok(false) when one was there.
+fn create_install_in_progress_marker_at(path: &Path) -> Result<bool, String> {
     let parent = path
         .parent()
         .ok_or_else(|| format!("Invalid install marker path: {}", path.display()))?;
@@ -71,8 +88,8 @@ fn create_install_in_progress_marker_at(path: &Path) -> Result<(), String> {
         .create_new(true)
         .open(path)
     {
-        Ok(_) => Ok(()),
-        Err(error) if error.kind() == std::io::ErrorKind::AlreadyExists => Ok(()),
+        Ok(_) => Ok(true),
+        Err(error) if error.kind() == std::io::ErrorKind::AlreadyExists => Ok(false),
         Err(error) => Err(format!("Failed to create {}: {}", path.display(), error)),
     }
 }
@@ -90,6 +107,7 @@ fn clear_install_marker_best_effort() {
     if let Err(msg) = clear_install_in_progress_marker() {
         warn!("[install] {}", msg);
     }
+    MARKER_CREATED_HERE.store(false, std::sync::atomic::Ordering::Relaxed);
 }
 
 fn clear_install_in_progress_marker_at(path: &Path) -> Result<(), String> {
@@ -516,10 +534,11 @@ fn run_install_with_event_mode(
     let (stdout, stderr) = match spawn_script(&script, &args, &state) {
         Ok(handles) => handles,
         Err(msg) => {
-            // Nothing ran, so nothing is half-installed. Unless another installer
-            // owns the marker, where clearing it drops its recovery signal.
+            // Nothing ran, so nothing is half-installed. Unless the marker is
+            // not ours: another installer owns it, or an earlier interrupted
+            // one left it, and either way its signal is not ours to drop.
             if msg != INSTALL_ALREADY_RUNNING {
-                clear_install_marker_best_effort();
+                clear_own_install_marker();
             }
             diagnostics::finish_attempt(
                 &diagnostics,
@@ -648,7 +667,7 @@ pub fn record_pending_elevation_canceled(
         return false;
     };
     // The resumed run the elevation exit left the marker for is not happening.
-    clear_install_marker_best_effort();
+    clear_own_install_marker();
     diagnostics::finish_attempt(
         diagnostics,
         &attempt,
@@ -922,7 +941,7 @@ fn finish_elevation_failure(
     message: String,
 ) {
     // Terminal, like a cancelled prompt: the resumed run is not happening.
-    clear_install_marker_best_effort();
+    clear_own_install_marker();
     if let Some(attempt) = attempt {
         diagnostics::finish_attempt(
             diagnostics,
@@ -971,10 +990,11 @@ mod tests {
         ));
         let marker = directory.join(INSTALL_IN_PROGRESS_MARKER);
 
-        create_install_in_progress_marker_at(&marker).unwrap();
+        assert!(create_install_in_progress_marker_at(&marker).unwrap());
         assert!(marker.is_file());
 
-        create_install_in_progress_marker_at(&marker).unwrap();
+        // A second attempt finds the first one's marker and does not own it.
+        assert!(!create_install_in_progress_marker_at(&marker).unwrap());
         assert!(marker.is_file());
 
         clear_install_in_progress_marker_at(&marker).unwrap();
diff --git a/unsloth_cli/commands/studio.py b/unsloth_cli/commands/studio.py
index a933235d6a..f06da08d90 100644
--- a/unsloth_cli/commands/studio.py
+++ b/unsloth_cli/commands/studio.py
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import csv
 import importlib.util
 import hashlib
 import hmac
@@ -301,18 +302,25 @@ def _recorded_files_missing(installed) -> bool:
     """Whether RECORD lists files the venv no longer has.
 
     An interrupted replace can recreate a package directory and stop part-way
-    through filling it, so the directory existing proves nothing. 6656 files
-    across studio.txt's closure cost 158ms, against a probe that imports the
-    backend, and __pycache__ is skipped because deleting it is not damage.
+    through filling it, so the directory existing proves nothing. RECORD is read
+    directly because Distribution.files drops entries that no longer exist,
+    which is exactly the set this looks for. 6656 files across studio.txt's
+    closure cost 158ms, and __pycache__ is skipped: deleting it is not damage.
     """
-    for recorded in installed.files or ():
-        parts = PurePosixPath(str(recorded)).parts
+    # egg-info has no RECORD, and its file lists say nothing about completeness.
+    record = installed.read_text("RECORD")
+    if record is None:
+        return False
+    for row in csv.reader(record.splitlines()):
+        if not row or not row[0]:
+            continue
+        parts = PurePosixPath(row[0]).parts
         # .dist-info is the metadata itself; .data and ../ land outside the tree.
         if parts[0] == ".." or parts[0].endswith((".dist-info", ".data")):
             continue
         if "__pycache__" in parts or parts[-1].endswith(".pyc"):
             continue
-        if not installed.locate_file(recorded).exists():
+        if not installed.locate_file(row[0]).exists():
             return True
     return False
 
diff --git a/unsloth_cli/tests/test_studio_runtime_readiness.py b/unsloth_cli/tests/test_studio_runtime_readiness.py
index 24a687a4c2..15fff78b11 100644
--- a/unsloth_cli/tests/test_studio_runtime_readiness.py
+++ b/unsloth_cli/tests/test_studio_runtime_readiness.py
@@ -93,7 +93,9 @@ def test_desktop_runtime_check_accepts_a_prerelease_over_a_floor(monkeypatch, ca
     monkeypatch.setattr(
         importlib.import_module("importlib.metadata"),
         "distribution",
-        lambda _name: SimpleNamespace(version = "2.0.0b1", files = [], requires = None),
+        lambda _name: SimpleNamespace(
+            version = "2.0.0b1", files = [], requires = None, read_text = lambda _n: None,
+        ),
     )
 
     studio.desktop_runtime_check(_json_output = True)
@@ -112,7 +114,9 @@ def test_desktop_runtime_check_rejects_version_mismatch(monkeypatch, capsys, tmp
     monkeypatch.setattr(
         importlib.import_module("importlib.metadata"),
         "distribution",
-        lambda _name: SimpleNamespace(version = "1.0", files = [], requires = None),
+        lambda _name: SimpleNamespace(
+            version = "1.0", files = [], requires = None, read_text = lambda _n: None,
+        ),
     )
 
     with pytest.raises(typer.Exit):
@@ -137,7 +141,9 @@ def test_desktop_runtime_check_rejects_metadata_without_an_unpacked_package(
     monkeypatch.setattr(
         importlib.import_module("importlib.metadata"),
         "distribution",
-        lambda _name: SimpleNamespace(version = "0.140.5", files = None, requires = None),
+        lambda _name: SimpleNamespace(
+            version = "0.140.5", files = None, requires = None, read_text = lambda _n: None,
+        ),
     )
 
     with pytest.raises(typer.Exit):
@@ -156,7 +162,9 @@ def _fake_distributions(monkeypatch, installed):
             version, requires = installed[name]
         except KeyError:
             raise metadata.PackageNotFoundError(name) from None
-        return SimpleNamespace(version = version, files = [], requires = requires)
+        return SimpleNamespace(
+            version = version, files = [], requires = requires, read_text = lambda _n: None,
+        )
 
     monkeypatch.setattr(metadata, "distribution", _distribution)
 
@@ -256,8 +264,12 @@ def test_a_root_pin_is_checked_even_when_a_dependency_names_it_first(monkeypatch
 
 def test_a_record_without_its_files_is_reported_missing(monkeypatch, capsys, tmp_path):
     """An interrupted replace can recreate the package directory and stop
-    part-way through filling it, so the directory existing proves nothing."""
+    part-way through filling it, so the directory existing proves nothing.
+
+    Built as a real dist-info rather than a stub: Distribution.files drops
+    entries that no longer exist, which is the whole set this looks for."""
     studio = importlib.import_module("unsloth_cli.commands.studio")
+    metadata = importlib.import_module("importlib.metadata")
     backend = tmp_path / "backend"
     requirements = backend / "requirements"
     requirements.mkdir(parents = True)
@@ -266,23 +278,20 @@ def test_a_record_without_its_files_is_reported_missing(monkeypatch, capsys, tmp
     monkeypatch.setattr(studio, "_load_run_module", lambda: run_mod)
 
     site_packages = tmp_path / "site-packages"
-    (site_packages / "structlog-25.1.0.dist-info").mkdir(parents = True)
-    installed = SimpleNamespace(
-        version = "25.1.0",
-        requires = None,
-        files = [
-            "structlog/__init__.py",
-            "structlog/processors.py",
-            "structlog/__pycache__/__init__.cpython-311.pyc",
-            "structlog-25.1.0.dist-info/RECORD",
-        ],
-        locate_file = lambda name: site_packages / name,
+    dist_info = site_packages / "structlog-25.1.0.dist-info"
+    dist_info.mkdir(parents = True)
+    (dist_info / "METADATA").write_text(
+        "Metadata-Version: 2.1\nName: structlog\nVersion: 25.1.0\n", encoding = "utf-8",
     )
-    monkeypatch.setattr(
-        importlib.import_module("importlib.metadata"),
-        "distribution",
-        lambda _name: installed,
+    (dist_info / "RECORD").write_text(
+        "structlog/__init__.py,,\n"
+        "structlog/processors.py,,\n"
+        "structlog/__pycache__/__init__.cpython-313.pyc,,\n"
+        "structlog-25.1.0.dist-info/RECORD,,\n",
+        encoding = "utf-8",
     )
+    installed = next(iter(metadata.distributions(path = [str(site_packages)])))
+    monkeypatch.setattr(metadata, "distribution", lambda _name: installed)
 
     with pytest.raises(typer.Exit):
         studio.desktop_runtime_check(_json_output = True)
@@ -295,6 +304,7 @@ def test_a_record_without_its_files_is_reported_missing(monkeypatch, capsys, tmp
         studio.desktop_runtime_check(_json_output = True)
     assert json.loads(capsys.readouterr().out)["module"] == "structlog"
 
+    # Complete, and the never-written .pyc must not count as damage.
     (site_packages / "structlog" / "processors.py").touch()
     studio.desktop_runtime_check(_json_output = True)
     assert json.loads(capsys.readouterr().out) == {"runtime_ready": True}