From 4633ce20954ab5c71f774ec8dd0c221ab897cc5d Mon Sep 17 00:00:00 2001
From: Zanie Blue <contact@zanie.dev>
Date: Tue, 23 Jun 2026 13:28:33 -0500
Subject: [PATCH] Make project environments relocatable under preview

---
 crates/uv/src/commands/project/mod.rs |  6 +--
 crates/uv/tests/sync/sync.rs          | 64 +++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/crates/uv/src/commands/project/mod.rs b/crates/uv/src/commands/project/mod.rs
index 11b20e79e8ee6..4507dcd7b0ad7 100644
--- a/crates/uv/src/commands/project/mod.rs
+++ b/crates/uv/src/commands/project/mod.rs
@@ -28,7 +28,7 @@ use uv_installer::{InstallationStrategy, SatisfiesResult, SitePackages};
 use uv_normalize::{DEV_DEPENDENCIES, DefaultGroups, ExtraName, GroupName, PackageName};
 use uv_pep440::{TildeVersionSpecifier, Version, VersionSpecifiers};
 use uv_pep508::MarkerTreeContents;
-use uv_preview::Preview;
+use uv_preview::{Preview, PreviewFeature};
 use uv_pypi_types::{ConflictItem, ConflictKind, ConflictSet, Conflicts};
 use uv_python::{
     BrokenLink, EnvironmentPreference, Interpreter, InvalidEnvironmentKind, PythonDownloads,
@@ -1551,7 +1551,7 @@ impl ProjectEnvironment {
                         uv_virtualenv::OnExisting::Remove(
                             uv_virtualenv::RemovalReason::ManagedEnvironment,
                         ),
-                        false,
+                        uv_preview::is_enabled(PreviewFeature::RelocatableEnvsDefault),
                         false,
                         upgradeable,
                     )?;
@@ -1591,7 +1591,7 @@ impl ProjectEnvironment {
                     uv_virtualenv::OnExisting::Remove(
                         uv_virtualenv::RemovalReason::ManagedEnvironment,
                     ),
-                    false,
+                    uv_preview::is_enabled(PreviewFeature::RelocatableEnvsDefault),
                     false,
                     upgradeable,
                 )?;
diff --git a/crates/uv/tests/sync/sync.rs b/crates/uv/tests/sync/sync.rs
index 6095a5b9a2cfe..b7ccd3b71e17b 100644
--- a/crates/uv/tests/sync/sync.rs
+++ b/crates/uv/tests/sync/sync.rs
@@ -50,6 +50,70 @@ fn sync() -> Result<()> {
     Ok(())
 }
 
+/// With `relocatable-envs-default`, project environments are relocatable by default.
+#[test]
+fn sync_relocatable_envs_default() -> Result<()> {
+    let context = uv_test::test_context!("3.12").with_filtered_counts();
+    let project_dir = context.temp_dir.child("project");
+    project_dir.create_dir_all()?;
+    project_dir.child("pyproject.toml").write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["black"]
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.sync()
+        .current_dir(project_dir.path())
+        .arg("--preview-features")
+        .arg("relocatable-envs-default"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + black==24.3.0
+     + click==8.1.7
+     + mypy-extensions==1.0.0
+     + packaging==24.0
+     + pathspec==0.12.1
+     + platformdirs==4.2.0
+    ");
+
+    project_dir
+        .child(".venv")
+        .child("pyvenv.cfg")
+        .assert(predicate::str::contains("relocatable = true"));
+
+    let relocated_dir = context.temp_dir.child("relocated");
+    fs_err::rename(project_dir.path(), relocated_dir.path())?;
+
+    uv_snapshot!(context.filters(), context.run()
+        .current_dir(relocated_dir.path())
+        .env_remove(EnvVars::VIRTUAL_ENV)
+        .arg("--no-sync")
+        .arg("black")
+        .arg("--version"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    black, 24.3.0 (compiled: yes)
+    Python (CPython) 3.12.[X]
+
+    ----- stderr -----
+    ");
+
+    Ok(())
+}
+
 /// Ensure that `uv sync` reuses remote wheels cached by `uv pip install`.
 #[test]
 fn sync_reuses_pip_install_wheel_cache() -> Result<()> {