Comment improvements and remove stray import

Author: raulcd

ci/pixi/asan/cpp/pixi.toml

@@ -36,7 +36,8 @@ binutils = "*"
 cmake = "*"
 
 [feature.test.tasks]
-# This path mangling feels extremely finicky. Investigate alternatives to make this more robust.
+# This path depends on pixi-build's internal work-directory layout.
+# Required for running C++ tests on Docker.
 test = "cd $(ls -d /arrow/ci/pixi/asan/cpp/.pixi/build/work/arrow-cpp-*/work/build | head -n 1) && ctest --output-on-failure"
 
 [package]
@@ -71,8 +72,7 @@ extra-args = [
   "-DARROW_WITH_SNAPPY=ON",
   "-DARROW_WITH_ZLIB=ON",
   "-DARROW_WITH_ZSTD=ON",
-  # libutf8proc on package-host-dependencies seems to fail.
-  # More investigation needed. In the meantime use bundled.
+  # libutf8proc on package-host-dependencies fails use Bundled.
   "-Dutf8proc_SOURCE=BUNDLED",
   "-DOPENSSL_ROOT_DIR=$PREFIX",
 ]

ci/pixi/default/cpp/pixi.toml

@@ -17,24 +17,25 @@
 
 [workspace]
 channels = ["https://prefix.dev/conda-forge"]
-platforms = ["linux-64", "linux-aarch64", "osx-arm64"]
+platforms = ["linux-64"]
 preview = ["pixi-build"]
 
 [environments]
 test    = ["test"]
 
-[feature.test.activation.env]                                                                                                                                                                                       
+[feature.test.activation.env]
 ARROW_TEST_DATA = "/arrow/testing/data"
 PARQUET_TEST_DATA = "/arrow/cpp/submodules/parquet-testing/data"
 
 [feature.test.dependencies]
 binutils = "*"
 cmake = "*"
-                                                                                                                                                                                           
+
 [feature.test.tasks]
-# This path mangling feels extremely finicky. Investigate alternatives to make this more robust.
+# This path depends on pixi-build's internal work-directory layout.
+# Required for running C++ tests on Docker.
 test = "cd $(ls -d /arrow/ci/pixi/default/cpp/.pixi/build/work/arrow-cpp-*/work/build | head -n 1) && ctest --output-on-failure"
-                                                                                                                                                                                                                      
+
 [package]
 name = "arrow-cpp"
 version = "25.0.0a0"
@@ -63,8 +64,7 @@ extra-args = [
   "-DARROW_WITH_SNAPPY=ON",
   "-DARROW_WITH_ZLIB=ON",
   "-DARROW_WITH_ZSTD=ON",
-  # libutf8proc on package-host-dependencies seems to fail.
-  # More investigation needed. In the meantime use bundled.
+  # libutf8proc on package-host-dependencies fails use Bundled.
   "-Dutf8proc_SOURCE=BUNDLED",
   "-DOPENSSL_ROOT_DIR=$PREFIX",
 ]

ci/pixi/default/python/pixi.toml

@@ -17,7 +17,7 @@
 
 [workspace]
 channels = ["https://prefix.dev/conda-forge"]
-platforms = ["linux-64", "linux-aarch64", "osx-arm64"]
+platforms = ["linux-64"]
 preview = ["pixi-build"]
 
 [environments]

python/pyarrow/lib.pyx

@@ -29,7 +29,6 @@ import os
 import sys
 
 from cython.operator cimport dereference as deref
-from libc.stdlib cimport malloc, free
 from pyarrow.includes.libarrow cimport *
 from pyarrow.includes.libarrow_python cimport *
 from pyarrow.includes.common cimport PyObject_to_object

python/pyarrow/tests/test_memory.py

@@ -257,21 +257,21 @@ def check_debug_memory_pool_disabled(pool_factory, env_value, msg):
         assert msg in res.stderr
 
 
-# Asan test fails as we are doing an out-of-bounds write.
+# Asan test fails as we are deliberately doing an out-of-bounds write.
 @pytest.mark.noasan
 @pytest.mark.parametrize('pool_factory', supported_factories())
 def test_debug_memory_pool_none(pool_factory):
     check_debug_memory_pool_disabled(pool_factory, "none", "")
 
 
-# Asan test fails as we are doing an out-of-bounds write.
+# Asan test fails as we are deliberately doing an out-of-bounds write.
 @pytest.mark.noasan
 @pytest.mark.parametrize('pool_factory', supported_factories())
 def test_debug_memory_pool_empty(pool_factory):
     check_debug_memory_pool_disabled(pool_factory, "", "")
 
 
-# Asan test fails as we are doing an out-of-bounds write.
+# Asan test fails as we are deliberately doing an out-of-bounds write.
 @pytest.mark.noasan
 @pytest.mark.parametrize('pool_factory', supported_factories())
 def test_debug_memory_pool_unknown(pool_factory):