Normalize relative paths when --project is specified

crates/uv-fs/src/path.rs

@@ -272,13 +272,16 @@ pub fn relative_to(
     path: impl AsRef<Path>,
     base: impl AsRef<Path>,
 ) -> Result<PathBuf, std::io::Error> {
+    // Normalize both paths, to avoid intermediate `..` components.
+    let path = normalize_path(path.as_ref());
+    let base = normalize_path(base.as_ref());
+
     // Find the longest common prefix, and also return the path stripped from that prefix
     let (stripped, common_prefix) = base
-        .as_ref()
         .ancestors()
         .find_map(|ancestor| {
             // Simplifying removes the UNC path prefix on windows.
-            dunce::simplified(path.as_ref())
+            dunce::simplified(&path)
                 .strip_prefix(dunce::simplified(ancestor))
                 .ok()
                 .map(|stripped| (stripped, ancestor))
@@ -288,14 +291,14 @@ pub fn relative_to(
                 std::io::ErrorKind::Other,
                 format!(
                     "Trivial strip failed: {} vs. {}",
-                    path.as_ref().simplified_display(),
-                    base.as_ref().simplified_display()
+                    path.simplified_display(),
+                    base.simplified_display()
                 ),
             )
         })?;
 
     // go as many levels up as required
-    let levels_up = base.as_ref().components().count() - common_prefix.components().count();
+    let levels_up = base.components().count() - common_prefix.components().count();
     let up = std::iter::repeat("..").take(levels_up).collect::<PathBuf>();
 
     Ok(up.join(stripped))

crates/uv/src/lib.rs

@@ -65,6 +65,8 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
         .as_deref()
         .map(std::path::absolute)
         .transpose()?
+        .as_deref()
+        .map(uv_fs::normalize_path)
         .map(Cow::Owned)
         .unwrap_or_else(|| Cow::Borrowed(&*CWD));
 

crates/uv/tests/it/lock.rs

@@ -6347,6 +6347,110 @@ fn lock_no_workspace_source() -> Result<()> {
     Ok(())
 }
 
+/// Lock a workspace with a member that's a peer to the root.
+#[test]
+fn lock_peer_member() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    context
+        .temp_dir
+        .child("project")
+        .child("pyproject.toml")
+        .write_str(
+            r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["child"]
+
+        [tool.uv.workspace]
+        members = ["../child"]
+
+        [tool.uv.sources]
+        child = { workspace = true }
+        "#,
+        )?;
+
+    context
+        .temp_dir
+        .child("child")
+        .child("pyproject.toml")
+        .write_str(
+            r#"
+        [project]
+        name = "child"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = []
+
+        [build-system]
+        requires = ["setuptools>=42"]
+        build-backend = "setuptools.build_meta"
+        "#,
+        )?;
+
+    uv_snapshot!(context.filters(), context.lock().current_dir(context.temp_dir.child("project")), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Resolved 2 packages in [TIME]
+    "###);
+
+    let lock = fs_err::read_to_string(context.temp_dir.child("project").child("uv.lock")).unwrap();
+
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            lock, @r###"
+        version = 1
+        requires-python = ">=3.12"
+
+        [options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+
+        [manifest]
+        members = [
+            "child",
+            "project",
+        ]
+
+        [[package]]
+        name = "child"
+        version = "0.1.0"
+        source = { editable = "../child" }
+
+        [[package]]
+        name = "project"
+        version = "0.1.0"
+        source = { virtual = "." }
+        dependencies = [
+            { name = "child" },
+        ]
+
+        [package.metadata]
+        requires-dist = [{ name = "child", editable = "../child" }]
+        "###
+        );
+    });
+
+    // Re-run with `--locked`.
+    uv_snapshot!(context.filters(), context.lock().arg("--locked"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: No `pyproject.toml` found in current directory or any parent directory
+    "###);
+
+    Ok(())
+}
+
 /// Ensure that development dependencies are omitted for non-workspace members. Below, `bar` depends
 /// on `foo`, but `bar/uv.lock` should omit `anyio`, but should include `typing-extensions`.
 #[test]
@@ -18886,6 +18990,107 @@ fn mismatched_name_self_editable() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn lock_relative_project() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    context
+        .temp_dir
+        .child("project")
+        .child("pyproject.toml")
+        .write_str(
+            r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["typing-extensions"]
+        "#,
+        )?;
+
+    let peer = context.temp_dir.child("peer");
+    fs_err::create_dir_all(&peer)?;
+
+    uv_snapshot!(context.filters(), context.lock().arg("--project").arg("../project").current_dir(&peer), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Resolved 2 packages in [TIME]
+    "###);
+
+    let lock = context.read(context.temp_dir.child("project").child("uv.lock"));
+
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            lock, @r###"
+        version = 1
+        requires-python = ">=3.12"
+
+        [options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+
+        [[package]]
+        name = "project"
+        version = "0.1.0"
+        source = { virtual = "." }
+        dependencies = [
+            { name = "typing-extensions" },
+        ]
+
+        [package.metadata]
+        requires-dist = [{ name = "typing-extensions" }]
+
+        [[package]]
+        name = "typing-extensions"
+        version = "4.10.0"
+        source = { registry = "https://pypi.org/simple" }
+        sdist = { url = "https://files.pythonhosted.org/packages/16/3a/0d26ce356c7465a19c9ea8814b960f8a36c3b0d07c323176620b7b483e44/typing_extensions-4.10.0.tar.gz", hash = "sha256:b0abd7c89e8fb96f98db18d86106ff1d90ab692004eb746cf6eda2682f91b3cb", size = 77558 }
+        wheels = [
+            { url = "https://files.pythonhosted.org/packages/f9/de/dc04a3ea60b22624b51c703a84bbe0184abcd1d0b9bc8074b5d6b7ab90bb/typing_extensions-4.10.0-py3-none-any.whl", hash = "sha256:69b1a937c3a517342112fb4c6df7e72fc39a38e7891a5730ed4985b5214b5475", size = 33926 },
+        ]
+        "###
+        );
+    });
+
+    // Re-run with `--locked`.
+    uv_snapshot!(context.filters(), context.lock().arg("--locked").arg("--project").arg("../project").current_dir(&peer), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Resolved 2 packages in [TIME]
+    "###);
+
+    // Create a virtual environment in the project directory.
+    context
+        .command()
+        .arg("venv")
+        .current_dir(context.temp_dir.child("project"))
+        .assert()
+        .success();
+
+    // Install from the lockfile.
+    uv_snapshot!(context.filters(), context.sync().arg("--frozen").arg("--project").arg("../project").current_dir(&peer), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + typing-extensions==4.10.0
+    "###);
+
+    Ok(())
+}
+
 #[test]
 fn lock_recursive_extra() -> Result<()> {
     let context = TestContext::new("3.12");