From 18ef350a197fb054fdf0ab33dcb255d3f917bfa6 Mon Sep 17 00:00:00 2001
From: Hiroshi Shinaoka <h.shinaoka@gmail.com>
Date: Mon, 6 Apr 2026 17:42:13 +0900
Subject: [PATCH] pin GitHub fallback tensor4all-rs commit

---
 README.md                 | 2 +-
 deps/build.jl             | 7 ++++---
 test/runtests.jl          | 1 +
 test/test_build_script.jl | 9 +++++++++
 4 files changed, 15 insertions(+), 4 deletions(-)
 create mode 100644 test/test_build_script.jl

diff --git a/README.md b/README.md
index acec74d..5aa3eaf 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ The build script locates the `tensor4all-rs` Rust workspace in this priority ord
 
 1. `TENSOR4ALL_RS_PATH` environment variable
 2. Sibling directory `../tensor4all-rs/` (relative to the package root)
-3. Automatic clone from GitHub
+3. Automatic clone from GitHub at the pinned fallback commit in [deps/build.jl](deps/build.jl)
 
 ## Running Tests
 
diff --git a/deps/build.jl b/deps/build.jl
index 2ed2000..ece2851 100644
--- a/deps/build.jl
+++ b/deps/build.jl
@@ -12,7 +12,7 @@ using Libdl
 using RustToolChain: cargo
 
 # Configuration
-const TENSOR4ALL_RS_VERSION = "main"  # Branch, tag, or commit hash
+const TENSOR4ALL_RS_FALLBACK_COMMIT = "8a68db84d517286ee55fda3585eebb26667e200a"
 const TENSOR4ALL_RS_REPO = "https://github.com/tensor4all/tensor4all-rs.git"
 
 # Paths
@@ -59,8 +59,9 @@ end
 Clone tensor4all-rs from GitHub to the specified directory.
 """
 function clone_from_github(dest::String)
-    println("Cloning tensor4all-rs from GitHub (version: $TENSOR4ALL_RS_VERSION)...")
-    run(`git clone --depth 1 --branch $TENSOR4ALL_RS_VERSION $TENSOR4ALL_RS_REPO $dest`)
+    println("Cloning tensor4all-rs from GitHub (pinned commit: $TENSOR4ALL_RS_FALLBACK_COMMIT)...")
+    run(`git clone $TENSOR4ALL_RS_REPO $dest`)
+    run(`git -C $dest checkout --detach $TENSOR4ALL_RS_FALLBACK_COMMIT`)
 end
 
 """
diff --git a/test/runtests.jl b/test/runtests.jl
index 97bfcd9..5b1b823 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -9,6 +9,7 @@ const T4ATensor = Tensor4all.Tensor
 skip_hdf5 = get(ENV, "T4A_SKIP_HDF5_TESTS", "") == "1"
 
 @testset "Tensor4all.jl" begin
+    include("test_build_script.jl")
     include("test_index.jl")
     include("test_tensor.jl")
     include("test_treetn.jl")
diff --git a/test/test_build_script.jl b/test/test_build_script.jl
new file mode 100644
index 0000000..6e98a6e
--- /dev/null
+++ b/test/test_build_script.jl
@@ -0,0 +1,9 @@
+using Test
+
+@testset "build.jl" begin
+    script = read(joinpath(dirname(@__DIR__), "deps", "build.jl"), String)
+
+    @test occursin(r"const TENSOR4ALL_RS_FALLBACK_COMMIT = \"[0-9a-f]{40}\"", script)
+    @test occursin("checkout --detach", script)
+    @test !occursin("--branch", script)
+end