[charliermarsh]

Summary

Allow uv workspace metadata --frozen to discover uv.lock when the workspace manifest is unavailable. We emit a preview warning unless --preview-features frozen-lockfile is enabled. We discover an existing environment relative to the lockfile and include its environment metadata and module ownership.

We derive member identities and paths from the lockfile even when workspace manifests are available, so frozen metadata stays consistent when a manifest moves a member.

Lockfile-only metadata requires revision 5 or later. --sync requires the workspace manifest in this PR; #22018 adds support for syncing without it.

[codspeed]

Merging this PR will not alter performance

✅ 54 untouched benchmarks
⏩ 47 skipped benchmarks¹

---

_{Comparing charlie/frozen-lockfile-metadata (5a6c4cc) with charlie/frozen-lockfile-tree (7cf6cda)}

Footnotes

1. 47 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[EliteTK]

This problem was introduced in #22103 but only shows up here:

#!/usr/bin/env bash

set -e

tmpdir=$(mktemp -d)
trap 'rm -rf "$tmpdir"' EXIT
cd "$tmpdir"
tmpdir=$(pwd -P)

mkdir foo bar other

cat >pyproject.toml <<EOF
[project]
name = "root"
version = "1.0"
requires-python = ">=3.9"
dependencies = ["bar"]

[tool.uv.sources]
bar = { path = "bar" }

[tool.uv.workspace]
members = ["foo"]

[tool.uv]
conflicts = [[{ package = "root" }, { package = "foo" }]]
EOF

cat >foo/pyproject.toml <<EOF
[project]
name = "foo"
version = "1.0"
EOF

cat >other/pyproject.toml <<EOF
[project]
name = "foo"
version = "2.0"

[build-system]
requires = []
build-backend = "example"
EOF

cat >bar/pyproject.toml <<EOF
[project]
name = "bar"
version = "1.0"
dependencies = ["foo @ file://$tmpdir/other"]

[build-system]
requires = []
build-backend = "example"
EOF

uv lock --offline --quiet --preview-features package-conflicts

args=(workspace metadata --offline
	--preview-features workspace-metadata,frozen-lockfile,package-conflicts)

set -x

uv "${args[@]}" >before
rm pyproject.toml foo/pyproject.toml bar/pyproject.toml other/pyproject.toml
uv "${args[@]}" --frozen >after
diff -u before after || true

output:

+ uv workspace metadata --offline --preview-features workspace-metadata,frozen-lockfile,package-conflicts
Using CPython 3.14.0
Resolved 4 packages in 8ms
+ rm pyproject.toml foo/pyproject.toml bar/pyproject.toml other/pyproject.toml
+ uv workspace metadata --offline --preview-features workspace-metadata,frozen-lockfile,package-conflicts --frozen
+ diff -u before after
--- before	2026-10-02 14:48:24
+++ after	2026-10-02 14:48:24
@@ -15,7 +15,7 @@
           {
             "package": "foo",
             "kind": "Project",
-            "id": "foo==1.0@virtual+.../tmp.2DVqnbZd9z/foo"
+            "id": "foo==2.0@directory+.../tmp.2DVqnbZd9z/other"
           },
           {
             "package": "root",
@@ -29,12 +29,7 @@
   "members": [
     {
       "name": "foo",
-      "path": ".../tmp.2DVqnbZd9z/foo",
-      "id": "foo==1.0@virtual+.../tmp.2DVqnbZd9z/foo"
-    },
-    {
-      "name": "foo",
-      "path": ".../tmp.2DVqnbZd9z/foo",
+      "path": ".../tmp.2DVqnbZd9z/other",
       "id": "foo==2.0@directory+.../tmp.2DVqnbZd9z/other"
     },
     {
+ true
+ rm -rf .../tmp.2DVqnbZd9z

We look up workspace members by package name only, which is insufficient here.

Looks good aside from that.

[EliteTK]

Isn't this more of a MetadataSource?

[EliteTK]

It seems weird to have from_lock and now from_lockfile. One is the workspace oriented version, and the other is the frozen lockfile-only variant. Seems like something should be renamed.