@@ -77,16 +77,23 @@ jobs:
       - name: Apply lancedb patches
         run: git apply -v python-wheels/patches/lancedb/${{ env.LANCEDB_VERSION }}/0001*.patch
 
+      # lancedb pins lance-core/lance-linalg to a different exact version per
+      # release (10.0.0 for v0.37.1, 11.0.0 for v0.38.0, 12.0.0 for v0.39.0),
+      # so the sibling checkout below must track whatever this lancedb tag's
+      # own Cargo.toml pins rather than a fixed tag.
+      - name: Determine the lance-core/lance-linalg version lancedb pins
+        run: echo "LANCE_VERSION=$(grep -m1 '^lance-core = ' Cargo.toml | grep -oE '[0-9]+\.[0-9]+\.[0-9]+')" >> "$GITHUB_ENV"
+
       # lance-core's SIMD_SUPPORT static and lance-linalg's f32x8/f32x16/
       # i32x8/f64x4/f64x8 SIMD types compile only for x86_64/aarch64/
       # loongarch64 upstream; the 0002 patch adds a portable riscv64 fallback
       # to this checkout, and Cargo.toml's `[patch.crates-io]` (0001) redirects
       # both crates here.
-      - name: Checkout lance v10.0.0 and add a riscv64 SIMD fallback
+      - name: Checkout lance v${{ env.LANCE_VERSION }} and add a riscv64 SIMD fallback
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
         with:
           repository: lancedb/lance
-          ref: v10.0.0
+          ref: v${{ env.LANCE_VERSION }}
           path: lance
           persist-credentials: false
 
@@ -144,18 +151,38 @@ jobs:
             CARGO_BUILD_JOBS=2
             PIP_EXTRA_INDEX_URL=https://pypi.riseproject.dev/simple/
           # Without this pip prefers PyPI's releases, which have no riscv64
-          # wheel for these, and source-builds them in the container.
-          CIBW_TEST_ENVIRONMENT: PIP_ONLY_BINARY=numpy,pandas,pyarrow,duckdb,pydantic-core
-          CIBW_TEST_REQUIRES: pytest pytest-asyncio numpy pandas pyarrow duckdb
+          # wheel for these, and source-builds them in the container. pylance
+          # is pinned to our registry's exact published version (not just
+          # named) per gotcha 30: with PIP_EXTRA_INDEX_URL alone pip picks the
+          # highest version across both indexes, and PyPI's latest pylance is
+          # newer than what pypi.riseproject.dev hosts, so an unpinned
+          # `pylance` would resolve to a PyPI release with no riscv64 wheel
+          # and source-build the whole lance Rust workspace here.
+          CIBW_TEST_ENVIRONMENT: PIP_ONLY_BINARY=numpy,pandas,pyarrow,duckdb,pydantic-core,pylance
+          CIBW_TEST_REQUIRES: pytest pytest-asyncio numpy pandas pyarrow duckdb pylance==11.0.0
           CIBW_TEST_SOURCES: python/pyproject.toml python/python/tests
           # test_table.py, test_util.py, test_embeddings.py and
           # test_namespace_integration.py import `polars` and/or `lance`
-          # (pylance) unconditionally at module scope, as do
-          # docs/test_guide_tables.py and docs/test_python.py; neither package
-          # has a riscv64 wheel and both are large enough Rust projects in
-          # their own right that building them from source here is out of
-          # scope, so those six files fail collection and are excluded rather
-          # than left to error. Otherwise mirrors run_tests/action.yml's
+          # (pylance) and/or `lance_namespace` unconditionally at module
+          # scope, as do docs/test_guide_tables.py and docs/test_python.py;
+          # polars has no riscv64 wheel and is a large enough Rust project in
+          # its own right that building it from source here is out of scope,
+          # so those six files fail collection and stay excluded. This was
+          # not re-checked file-by-file against pylance's newer availability
+          # below -- only test_blob.py, the one file CI actually reported
+          # failing here, was fixed rather than excluded.
+          #
+          # test_blob.py imports `lance` (the pylance package) unconditionally
+          # at module scope too, but is new in 0.38.0/0.39.0 (not present in
+          # 0.37.1, when the six-file exclusion above was established) so it
+          # was never checked against pylance's availability until now. It
+          # isn't excluded because pypi.riseproject.dev already hosts a
+          # pylance riscv64 wheel (see docs/packages/pylance.yaml, added to
+          # CIBW_TEST_REQUIRES above) and lance's python/python/lance/blob.py
+          # is unchanged between the v9.0.0 pylance/lance release lancedb's
+          # own pyproject.toml `tests` extra pins and the v11.0.0 this repo
+          # publishes, aside from an added BlobFile.read_ranges method
+          # test_blob.py doesn't use. Otherwise mirrors run_tests/action.yml's
           # non-integration path (`-m "not slow and not s3_test"`, no docker
           # compose/localstack).
           #
@@ -179,6 +206,19 @@ jobs:
           # identically either way) and the tests run and fail anyway, as seen
           # in CI run 33843581031. `cd python` first puts pyproject.toml back
           # in the search path so --deselect (and the -m marker filter) work.
+          #
+          # test_first_class_function_slice1.py/slice2.py are new (0.38.0/
+          # 0.39.0) and hit the exact same class of trap as
+          # test_pyo3_abi_matches_minimum_supported_python above: they read
+          # golden fixtures from outside the CIBW_TEST_SOURCES tree --
+          # docs/src/python/python.md and rust/lancedb/tests/fixtures/
+          # first_class_functions/v1/*.json, both siblings of python/ in the
+          # full checkout but not copied into the isolated test dir (only
+          # pyproject.toml and python/tests are) -- and fail with the same
+          # FileNotFoundError regardless of platform. They assert Python/Rust
+          # golden-contract and docs consistency, not installed-wheel runtime
+          # behavior, so ignore both files rather than widen
+          # CIBW_TEST_SOURCES to mirror docs/ and rust/'s layout.
           CIBW_TEST_COMMAND: >-
             cd python &&
             python -m pytest python/tests -vv --durations=30
@@ -189,6 +229,8 @@ jobs:
             --ignore=python/tests/test_namespace_integration.py
             --ignore=python/tests/docs/test_guide_tables.py
             --ignore=python/tests/docs/test_python.py
+            --ignore=python/tests/test_first_class_function_slice1.py
+            --ignore=python/tests/test_first_class_function_slice2.py
             --deselect=python/tests/test_db.py::test_create_table_stable_row_ids_via_storage_options
             --deselect=python/tests/test_db.py::test_create_table_stable_row_ids_via_storage_options_sync
             --deselect=python/tests/test_db.py::test_create_table_stable_row_ids_table_level_override
 
@@ -9,3 +9,5 @@ versions:
   - filename: lancedb-0.37.1-cp310-abi3-manylinux_2_39_riscv64.whl
     sha256: 405656a126ed0c70028834c5370463e3e2b5f9b53dc7ef36a6d79b000ee276ac
     requires-python: '>=3.10'
+- version: 0.38.0
+- version: 0.39.0
@@ -0,0 +1,64 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Thu, 03 Sep 2026 00:00:00 +0000
+Subject: [PATCH] cargo: redirect lance-core/lance-linalg to a riscv64-patched
+ checkout
+
+lance-core's SIMD_SUPPORT static (rust/lance-core/src/utils/cpu.rs) and
+lance-linalg's f32x8/f32x16/i32x8/f64x4/f64x8 SIMD types
+(rust/lance-linalg/src/simd/{f32,i32,f64}.rs) are compiled for
+x86_64/aarch64/loongarch64 only, with no fallback arm for any other
+architecture: the SIMD_SUPPORT closure has no trailing expression on
+riscv64 ("expected SimdSupport, found ()"), and the SIMD type structs are
+defined only under those three `#[cfg(target_arch = ...)]` attributes
+while every method implementing them is unconditional, so riscv64 hits
+"cannot find type `f32x8` in this scope" as soon as lance-linalg is
+built.
+
+Both crates are pulled in from crates.io at a pinned `=10.0.0`, so the
+fix cannot be applied in place. Redirect them to a checkout of the same
+v10.0.0 tag carrying a portable scalar fallback for both, see
+0002-lance-linalg-add-a-portable-riscv64-simd-fallback.patch. `exclude`
+keeps that checkout's own [workspace] from being silently absorbed into
+this one, which would drop its `[workspace.package]` inheritance
+(version, edition, ...) for lance-core and lance-linalg.
+
+Only the source line of the lance-core/lance-linalg entries changes in
+Cargo.lock, so every other dependency stays pinned exactly as upstream
+released it.
+
+Upstream-Status: Inappropriate [redirects two pinned dependencies to a local checkout; the fix itself belongs in lancedb/lance]
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ Cargo.toml | 12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+
+diff --git a/Cargo.toml b/Cargo.toml
+index a47e59e..ab6cf5c 100644
+--- a/Cargo.toml
++++ b/Cargo.toml
+@@ -1,5 +1,10 @@
+ [workspace]
+ members = ["rust/lancedb", "nodejs", "python"]
++# ./lance (see [patch.crates-io] below) carries its own [workspace]; excluding
++# it keeps that workspace independent instead of being silently absorbed into
++# this one, which would drop its `[workspace.package]` inheritance (version,
++# edition, ...) for lance-core and lance-linalg.
++exclude = ["lance"]
+ resolver = "2"
+ 
+ [workspace.package]
+@@ -80,3 +85,10 @@ debug = false
+ debug-assertions = false
+ strip = "debuginfo"
+ incremental = false
++
++# lance-core's SIMD_SUPPORT and lance-linalg's f32x8/f32x16/i32x8/f64x4/f64x8
++# SIMD types compile only for x86_64/aarch64/loongarch64 upstream; ./lance is
++# the same v10.0.0 tag with a riscv64 scalar fallback added to both.
++[patch.crates-io]
++lance-core = { path = "lance/rust/lance-core" }
++lance-linalg = { path = "lance/rust/lance-linalg" }
+-- 
+2.43.0