MacOS `clang` Build With 3rdparty `possionrecon` Fails at `build/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl`

[essandess]

Checklist

• I have searched for similar issues.
• For Python issues, I have tested with the latest development wheel.
• I have checked the release documentation and the latest documentation (for main branch).

Steps to reproduce the issue

I’ve submitted a MacPorts Portfile for Open3D at macports/macports-ports#32787

The clang build fails when compiling possionrecon at build/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl with error:

build/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl:466:24: error: reference to non-static member function must be called
  466 |         for( size_t i=0 ; i<A.rows ; i++ )
      |                             ~~^~~~

A hack fix is in this patch of cpp/open3d/ml/impl/misc/VoxelPooling.h, which hacks into the cmake build a patch of ${CMAKE_BINARY_DIR}/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl that edits A.rows into A.rows() at lines 466 and 499:

--- ./3rdparty/possionrecon/possionrecon.cmake	2026-05-15 12:38:49
+++ ./3rdparty/possionrecon/possionrecon.cmake	2026-05-16 00:42:33
@@ -1,5 +1,27 @@
 include(ExternalProject)
 
+# Fix https://github.com/isl-org/Open3D/issues/7390
+# A.rows() rather than A.rows
+set(PATCH_SCRIPT_NAME "fix_issue_7390.sh")
+set(PATCH_SCRIPT_PATH "${CMAKE_SOURCE_DIR}/3rdparty/possionrecon/${PATCH_SCRIPT_NAME}")
+if(NOT EXISTS "${PATCH_SCRIPT_PATH}")
+    file(GENERATE
+        OUTPUT "${PATCH_SCRIPT_PATH}" 
+        CONTENT "#!/bin/bash -x
+
+if [ -f ${CMAKE_BINARY_DIR}/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl ] $<SEMICOLON> then
+    for lineno in 466 499 $<SEMICOLON> do
+        sed -E -i '' \"\$\{lineno\}s|(A\\.rows)([[:space:]]+)|\\1()\\2|\" \\
+            ${CMAKE_BINARY_DIR}/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl \\
+            && echo 'sed -E SUCCESSFUL' || echo 'sed -E FAILED' $<SEMICOLON>
+    done $<SEMICOLON>
+else
+   echo \"File '${CMAKE_BINARY_DIR}/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl' NOT FOUND!\" $<SEMICOLON>
+fi"
+        FILE_PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
+    )
+endif()
+
 ExternalProject_Add(
     ext_poisson
     PREFIX poisson
@@ -10,7 +32,13 @@
     UPDATE_COMMAND ""
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
-    INSTALL_COMMAND ""

+    # INSTALL_COMMAND ""
+
+    INSTALL_COMMAND bash -x -c "if [ -x ${PATCH_SCRIPT_PATH} ] $<SEMICOLON> then \
+            ${PATCH_SCRIPT_PATH} $<SEMICOLON> \
+        else \
+            echo '${PATCH_SCRIPT_PATH} NOT FOUND!' $<SEMICOLON> \
+        fi"
 )

ExternalProject_Get_Property(ext_poisson SOURCE_DIR)

Additional information

Related: #7390

Error message

build/poisson/src/ext_poisson/PoissonRecon/Src/SparseMatrix.inl:466:24: error: reference to non-static member function must be called
  466 |         for( size_t i=0 ; i<A.rows ; i++ )
      |                             ~~^~~~

Open3D, Python and System information

- Operating system: macOS 26
- Python version: Python 3.14`
- Open3D version: 0.19.0`
- System architecture: arm64
- Is this a remote workstation?: no
- How did you install Open3D?: build from source
- Compiler version (if built from source): clang

Additional information

No response

[ssheorey]

Hi @essandess we don't get this error in our macOS CI. This looks like an old issue that has been already fixed. Please follow the .github/workflows/macos.yml recipe.