Fix handling of changes to requires-python

crates/uv-resolver/src/lock/mod.rs

@@ -768,6 +768,36 @@ impl Lock {
         }
     }
 
+    /// Checks whether the new requires-python specification is disjoint with
+    /// the fork markers in this lock file.
+    ///
+    /// If they are disjoint, then the union of the fork markers along with the
+    /// given requires-python specification (converted to a marker tree) are
+    /// returned.
+    ///
+    /// When disjoint, the fork markers in the lock file should be dropped and
+    /// not used.
+    pub fn requires_python_coverage(
+        &self,
+        new_requires_python: &RequiresPython,
+    ) -> Result<(), (MarkerTree, MarkerTree)> {
+        let fork_markers_union = if self.fork_markers().is_empty() {
+            self.requires_python.to_marker_tree()
+        } else {
+            let mut fork_markers_union = MarkerTree::FALSE;
+            for fork_marker in self.fork_markers() {
+                fork_markers_union.or(fork_marker.pep508());
+            }
+            fork_markers_union
+        };
+        let new_requires_python = new_requires_python.to_marker_tree();
+        if fork_markers_union.is_disjoint(new_requires_python) {
+            Err((fork_markers_union, new_requires_python))
+        } else {
+            Ok(())
+        }
+    }
+
     /// Returns the TOML representation of this lockfile.
     pub fn to_toml(&self) -> Result<String, toml_edit::ser::Error> {
         // Catch a lockfile where the union of fork markers doesn't cover the supported

crates/uv/src/commands/project/lock.rs

@@ -983,13 +983,54 @@ impl ValidatedLock {
                 return Ok(Self::Unusable(lock));
             }
             Upgrade::Packages(_) => {
-                // If the user specified `--upgrade-package`, then at best we can prefer some of
-                // the existing versions.
-                debug!("Ignoring existing lockfile due to `--upgrade-package`");
-                return Ok(Self::Preferable(lock));
+                // This is handled below, after some checks regarding fork
+                // markers. In particular, we'd like to return `Preferable`
+                // here, but we shouldn't if the fork markers cannot be
+                // reused.
             }
         }
 
+        // NOTE: It's important that this appears before any possible path that
+        // returns `Self::Preferable`. In particular, if our fork markers are
+        // bunk, then we shouldn't return a result that indicates we should try
+        // to re-use the existing fork markers.
+        if let Err((fork_markers_union, environments_union)) = lock.check_marker_coverage() {
+            warn_user!(
+                "Ignoring existing lockfile due to fork markers not covering the supported environments: `{}` vs `{}`",
+                fork_markers_union
+                    .try_to_string()
+                    .unwrap_or("true".to_string()),
+                environments_union
+                    .try_to_string()
+                    .unwrap_or("true".to_string()),
+            );
+            return Ok(Self::Versions(lock));
+        }
+
+        // NOTE: Similarly as above, this should also appear before any
+        // possible code path that can return `Self::Preferable`.
+        if let Err((fork_markers_union, requires_python_marker)) =
+            lock.requires_python_coverage(requires_python)
+        {
+            warn_user!(
+                "Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `{}` vs `{}`",
+                fork_markers_union
+                    .try_to_string()
+                    .unwrap_or("true".to_string()),
+                requires_python_marker
+                    .try_to_string()
+                    .unwrap_or("true".to_string()),
+            );
+            return Ok(Self::Versions(lock));
+        }
+
+        if let Upgrade::Packages(_) = upgrade {
+            // If the user specified `--upgrade-package`, then at best we can prefer some of
+            // the existing versions.
+            debug!("Ignoring existing lockfile due to `--upgrade-package`");
+            return Ok(Self::Preferable(lock));
+        }
+
         // If the Requires-Python bound has changed, we have to perform a clean resolution, since
         // the set of `resolution-markers` may no longer cover the entire supported Python range.
         if lock.requires_python().range() != requires_python.range() {
@@ -1022,19 +1063,6 @@ impl ValidatedLock {
             return Ok(Self::Versions(lock));
         }
 
-        if let Err((fork_markers_union, environments_union)) = lock.check_marker_coverage() {
-            warn_user!(
-                "Ignoring existing lockfile due to fork markers not covering the supported environments: `{}` vs `{}`",
-                fork_markers_union
-                    .try_to_string()
-                    .unwrap_or("true".to_string()),
-                environments_union
-                    .try_to_string()
-                    .unwrap_or("true".to_string()),
-            );
-            return Ok(Self::Versions(lock));
-        }
-
         // If the set of required platforms has changed, we have to perform a clean resolution.
         let expected = lock.simplified_required_environments();
         let actual = required_environments

crates/uv/tests/it/lock.rs

@@ -4731,15 +4731,16 @@ fn lock_requires_python_wheels() -> Result<()> {
         "#,
     )?;
 
-    uv_snapshot!(context.filters(), context.lock(), @r###"
+    uv_snapshot!(context.filters(), context.lock(), @r"
     success: true
     exit_code: 0
     ----- stdout -----
 
     ----- stderr -----
     Using CPython 3.11.[X] interpreter at: [PYTHON-3.11]
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version == '3.12.*'` vs `python_full_version == '3.11.*'`
     Resolved 2 packages in [TIME]
-    "###);
+    ");
 
     let lock = fs_err::read_to_string(&lockfile).unwrap();
 
@@ -28020,6 +28021,170 @@ fn lock_conflict_for_disjoint_python_version() -> Result<()> {
     Ok(())
 }
 
+/// Check that we hint if the resolution failed for a different platform.
+#[cfg(feature = "python-patch")]
+#[test]
+fn lock_requires_python_empty_lock_file() -> Result<()> {
+    // N.B. These versions were selected based on what was
+    // in `.python-versions` at the time of writing (2025-06-16).
+    let (v1, v2) = ("3.13.0", "3.13.2");
+    let context = TestContext::new_with_versions(&[v1, v2]);
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(&format!(
+        r#"
+        [project]
+        name = "renovate-bug-repro"
+        version = "0.1.0"
+        requires-python = "=={v1}"
+        dependencies = ["opencv-python-headless>=4.8"]
+        "#,
+    ))?;
+
+    uv_snapshot!(context.filters(), context.lock(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.13.0 interpreter at: [PYTHON-3.13.0]
+    Resolved 3 packages in [TIME]
+    ");
+
+    let lock = context.read("uv.lock");
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            lock, @r#"
+        version = 1
+        revision = 2
+        requires-python = "==3.13.0"
+        resolution-markers = [
+            "sys_platform == 'darwin'",
+            "platform_machine == 'aarch64' and sys_platform == 'linux'",
+            "(platform_machine != 'aarch64' and sys_platform == 'linux') or (sys_platform != 'darwin' and sys_platform != 'linux')",
+        ]
+
+        [options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+
+        [[package]]
+        name = "numpy"
+        version = "1.26.4"
+        source = { registry = "https://pypi.org/simple" }
+        sdist = { url = "https://files.pythonhosted.org/packages/65/6e/09db70a523a96d25e115e71cc56a6f9031e7b8cd166c1ac8438307c14058/numpy-1.26.4.tar.gz", hash = "sha256:2a02aba9ed12e4ac4eb3ea9421c420301a0c6460d9830d74a9df87efa4912010", size = 15786129, upload-time = "2024-02-06T00:26:44.495Z" }
+
+        [[package]]
+        name = "opencv-python-headless"
+        version = "4.9.0.80"
+        source = { registry = "https://pypi.org/simple" }
+        dependencies = [
+            { name = "numpy" },
+        ]
+        sdist = { url = "https://files.pythonhosted.org/packages/3d/b2/c308bc696bf5d75304175c62222ec8af9a6d5cfe36c14f19f15ea9d1a132/opencv-python-headless-4.9.0.80.tar.gz", hash = "sha256:71a4cd8cf7c37122901d8e81295db7fb188730e33a0e40039a4e59c1030b0958", size = 92910044, upload-time = "2023-12-31T13:34:50.518Z" }
+        wheels = [
+            { url = "https://files.pythonhosted.org/packages/ac/42/da433fca5733a3ce7e88dd0d4018f70dcffaf48770b5142250815f4faddb/opencv_python_headless-4.9.0.80-cp37-abi3-macosx_10_16_x86_64.whl", hash = "sha256:2ea8a2edc4db87841991b2fbab55fc07b97ecb602e0f47d5d485bd75cee17c1a", size = 55689478, upload-time = "2023-12-31T14:31:30.476Z" },
+            { url = "https://files.pythonhosted.org/packages/32/0c/a59f2a40d6058ee8126668dc5dff6977c913f6ecd21dbd15b41563409a18/opencv_python_headless-4.9.0.80-cp37-abi3-macosx_11_0_arm64.whl", hash = "sha256:e0ee54e27be493e8f7850847edae3128e18b540dac1d7b2e4001b8944e11e1c6", size = 35354670, upload-time = "2023-12-31T16:38:31.588Z" },
+            { url = "https://files.pythonhosted.org/packages/36/37/225a1f8be42610ffecf677558311ab0f9dfdc63537c250a2bce76762a380/opencv_python_headless-4.9.0.80-cp37-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:57ce2865e8fec431c6f97a81e9faaf23fa5be61011d0a75ccf47a3c0d65fa73d", size = 28954368, upload-time = "2023-12-31T16:40:00.838Z" },
+            { url = "https://files.pythonhosted.org/packages/71/19/3c65483a80a1d062d46ae20faf5404712d25cb1dfdcaf371efbd67c38544/opencv_python_headless-4.9.0.80-cp37-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:976656362d68d9f40a5c66f83901430538002465f7db59142784f3893918f3df", size = 49591873, upload-time = "2023-12-31T13:34:44.316Z" },
+            { url = "https://files.pythonhosted.org/packages/10/98/300382ff6ddff3a487e808c8a76362e430f5016002fcbefb3b3117aad32b/opencv_python_headless-4.9.0.80-cp37-abi3-win32.whl", hash = "sha256:11e3849d83e6651d4e7699aadda9ec7ed7c38957cbbcb99db074f2a2d2de9670", size = 28488841, upload-time = "2023-12-31T13:34:31.974Z" },
+            { url = "https://files.pythonhosted.org/packages/20/44/458a0a135866f5e08266566b32ad9a182a7a059a894effe6c41a9c841ff1/opencv_python_headless-4.9.0.80-cp37-abi3-win_amd64.whl", hash = "sha256:a8056c2cb37cd65dfcdf4153ca16f7362afcf3a50d600d6bb69c660fc61ee29c", size = 38536073, upload-time = "2023-12-31T13:34:39.675Z" },
+        ]
+
+        [[package]]
+        name = "renovate-bug-repro"
+        version = "0.1.0"
+        source = { virtual = "." }
+        dependencies = [
+            { name = "opencv-python-headless" },
+        ]
+
+        [package.metadata]
+        requires-dist = [{ name = "opencv-python-headless", specifier = ">=4.8" }]
+        "#
+        );
+    });
+
+    pyproject_toml.write_str(&format!(
+        r#"
+        [project]
+        name = "renovate-bug-repro"
+        version = "0.1.0"
+        requires-python = "=={v2}"
+        dependencies = ["opencv-python-headless>=4.8"]
+        "#,
+    ))?;
+
+    uv_snapshot!(context.filters(), context.lock().arg("--upgrade-package=python"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.13.2 interpreter at: [PYTHON-3.13.2]
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version == '3.13.0'` vs `python_full_version == '3.13.2'`
+    Resolved 3 packages in [TIME]
+    ");
+
+    let lock = context.read("uv.lock");
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            lock, @r#"
+        version = 1
+        revision = 2
+        requires-python = "==3.13.2"
+        resolution-markers = [
+            "sys_platform == 'darwin'",
+            "platform_machine == 'aarch64' and sys_platform == 'linux'",
+            "(platform_machine != 'aarch64' and sys_platform == 'linux') or (sys_platform != 'darwin' and sys_platform != 'linux')",
+        ]
+
+        [options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+
+        [[package]]
+        name = "numpy"
+        version = "1.26.4"
+        source = { registry = "https://pypi.org/simple" }
+        sdist = { url = "https://files.pythonhosted.org/packages/65/6e/09db70a523a96d25e115e71cc56a6f9031e7b8cd166c1ac8438307c14058/numpy-1.26.4.tar.gz", hash = "sha256:2a02aba9ed12e4ac4eb3ea9421c420301a0c6460d9830d74a9df87efa4912010", size = 15786129, upload-time = "2024-02-06T00:26:44.495Z" }
+
+        [[package]]
+        name = "opencv-python-headless"
+        version = "4.9.0.80"
+        source = { registry = "https://pypi.org/simple" }
+        dependencies = [
+            { name = "numpy" },
+        ]
+        sdist = { url = "https://files.pythonhosted.org/packages/3d/b2/c308bc696bf5d75304175c62222ec8af9a6d5cfe36c14f19f15ea9d1a132/opencv-python-headless-4.9.0.80.tar.gz", hash = "sha256:71a4cd8cf7c37122901d8e81295db7fb188730e33a0e40039a4e59c1030b0958", size = 92910044, upload-time = "2023-12-31T13:34:50.518Z" }
+        wheels = [
+            { url = "https://files.pythonhosted.org/packages/ac/42/da433fca5733a3ce7e88dd0d4018f70dcffaf48770b5142250815f4faddb/opencv_python_headless-4.9.0.80-cp37-abi3-macosx_10_16_x86_64.whl", hash = "sha256:2ea8a2edc4db87841991b2fbab55fc07b97ecb602e0f47d5d485bd75cee17c1a", size = 55689478, upload-time = "2023-12-31T14:31:30.476Z" },
+            { url = "https://files.pythonhosted.org/packages/32/0c/a59f2a40d6058ee8126668dc5dff6977c913f6ecd21dbd15b41563409a18/opencv_python_headless-4.9.0.80-cp37-abi3-macosx_11_0_arm64.whl", hash = "sha256:e0ee54e27be493e8f7850847edae3128e18b540dac1d7b2e4001b8944e11e1c6", size = 35354670, upload-time = "2023-12-31T16:38:31.588Z" },
+            { url = "https://files.pythonhosted.org/packages/36/37/225a1f8be42610ffecf677558311ab0f9dfdc63537c250a2bce76762a380/opencv_python_headless-4.9.0.80-cp37-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:57ce2865e8fec431c6f97a81e9faaf23fa5be61011d0a75ccf47a3c0d65fa73d", size = 28954368, upload-time = "2023-12-31T16:40:00.838Z" },
+            { url = "https://files.pythonhosted.org/packages/71/19/3c65483a80a1d062d46ae20faf5404712d25cb1dfdcaf371efbd67c38544/opencv_python_headless-4.9.0.80-cp37-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:976656362d68d9f40a5c66f83901430538002465f7db59142784f3893918f3df", size = 49591873, upload-time = "2023-12-31T13:34:44.316Z" },
+            { url = "https://files.pythonhosted.org/packages/10/98/300382ff6ddff3a487e808c8a76362e430f5016002fcbefb3b3117aad32b/opencv_python_headless-4.9.0.80-cp37-abi3-win32.whl", hash = "sha256:11e3849d83e6651d4e7699aadda9ec7ed7c38957cbbcb99db074f2a2d2de9670", size = 28488841, upload-time = "2023-12-31T13:34:31.974Z" },
+            { url = "https://files.pythonhosted.org/packages/20/44/458a0a135866f5e08266566b32ad9a182a7a059a894effe6c41a9c841ff1/opencv_python_headless-4.9.0.80-cp37-abi3-win_amd64.whl", hash = "sha256:a8056c2cb37cd65dfcdf4153ca16f7362afcf3a50d600d6bb69c660fc61ee29c", size = 38536073, upload-time = "2023-12-31T13:34:39.675Z" },
+        ]
+
+        [[package]]
+        name = "renovate-bug-repro"
+        version = "0.1.0"
+        source = { virtual = "." }
+        dependencies = [
+            { name = "opencv-python-headless" },
+        ]
+
+        [package.metadata]
+        requires-dist = [{ name = "opencv-python-headless", specifier = ">=4.8" }]
+        "#
+        );
+    });
+
+    Ok(())
+}
+
 /// Check that we hint if the resolution failed for a different platform.
 #[test]
 fn lock_conflict_for_disjoint_platform() -> Result<()> {

crates/uv/tests/it/sync.rs

@@ -8140,22 +8140,23 @@ fn sync_dry_run() -> Result<()> {
         "#,
     )?;
 
-    uv_snapshot!(context.filters(), context.sync().arg("--dry-run"), @r###"
+    uv_snapshot!(context.filters(), context.sync().arg("--dry-run"), @r"
     success: true
     exit_code: 0
     ----- stdout -----
 
     ----- stderr -----
     Using CPython 3.9.[X] interpreter at: [PYTHON-3.9]
     Would replace existing virtual environment at: .venv
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version >= '3.12'` vs `python_full_version == '3.9.*'`
     Resolved 2 packages in [TIME]
     Would update lockfile at: uv.lock
     Would install 1 package
      + iniconfig==2.0.0
-    "###);
+    ");
 
     // Perform a full sync.
-    uv_snapshot!(context.filters(), context.sync(), @r###"
+    uv_snapshot!(context.filters(), context.sync(), @r"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -8164,10 +8165,11 @@ fn sync_dry_run() -> Result<()> {
     Using CPython 3.9.[X] interpreter at: [PYTHON-3.9]
     Removed virtual environment at: .venv
     Creating virtual environment at: .venv
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version >= '3.12'` vs `python_full_version == '3.9.*'`
     Resolved 2 packages in [TIME]
     Installed 1 package in [TIME]
      + iniconfig==2.0.0
-    "###);
+    ");
 
     let output = context.sync().arg("--dry-run").arg("-vv").output()?;
     let stderr = String::from_utf8_lossy(&output.stderr);
@@ -8658,6 +8660,7 @@ fn sync_locked_script() -> Result<()> {
 
     ----- stderr -----
     Recreating script environment at: [CACHE_DIR]/environments-v2/script-[HASH]
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version >= '3.11'` vs `python_full_version >= '3.8' and python_full_version < '3.11'`
     Resolved 6 packages in [TIME]
     error: The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.
     ");
@@ -8669,6 +8672,7 @@ fn sync_locked_script() -> Result<()> {
 
     ----- stderr -----
     Using script environment at: [CACHE_DIR]/environments-v2/script-[HASH]
+    warning: Ignoring existing lockfile due to fork markers being disjoint with `requires-python`: `python_full_version >= '3.11'` vs `python_full_version >= '3.8' and python_full_version < '3.11'`
     Resolved 6 packages in [TIME]
     Prepared 2 packages in [TIME]
     Installed 6 packages in [TIME]