From e93d90337301b109aa2010695eac33c7a9891f51 Mon Sep 17 00:00:00 2001
From: Rob Woolley <rob.woolley@windriver.com>
Date: Thu, 13 Aug 2026 20:06:50 -0400
Subject: [PATCH] Add python-numpy-include feature

The b2 python.jam file attempts to import the NumPy module to
determine whether the Boost.Python NumPy extension should be
enabled. This approach is problematic when cross-compiling,
particularly because NumPy includes C extensions built for the
target architecture.

Introduce the new python-numpy-include feature to avoid probing for
NumPy at build time by allowing the include path to be specified
explicitly.

This enables build systems to provide the correct NumPy include
directory, eliminating the need to import the NumPy module to find
the directory in site-packages.

Signed-off-by: Rob Woolley <rob.woolley@windriver.com>
---
 src/tools/python.jam | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/tools/python.jam b/src/tools/python.jam
index 1275ff0a15..d916e9bf5b 100644
--- a/src/tools/python.jam
+++ b/src/tools/python.jam
@@ -61,6 +61,9 @@ lib rt ;
 # installed in the development system's default paths.
 feature.feature pythonpath : : free optional path ;
 
+# Declare python-numpy-include as a free feature accepting a path
+feature.feature python-numpy-include : : free path ;
+
 # The best configured version of Python 2 and 3.
 py2-version = ;
 py3-version = ;
@@ -900,21 +903,33 @@ local rule configure ( version ? : cmd-or-prefix ? : includes * : libraries ? :
     # Discover the presence of NumPy
     #
     debug-message "Checking for NumPy..." ;
-    local full-cmd = "import sys; sys.stderr = sys.stdout; import numpy; print(numpy.get_include())" ;
-    local full-cmd = $(interpreter-cmd)" -c \"$(full-cmd)\"" ;
-    debug-message "running command '$(full-cmd)'" ;
-    local result = [ SHELL $(full-cmd) : strip-eol : exit-status ] ;
-    if $(result[2]) = 0
+
+    local custom-numpy = [ feature.get-values <python-numpy-include> : $(condition) ] ;
+
+    if $(custom-numpy)
     {
         .numpy = true ;
-        .numpy-include = $(result[1]) ;
+        .numpy-include = $(custom-numpy) ;
         debug-message "NumPy enabled" ;
     }
     else
     {
-        debug-message "NumPy disabled. Reason:" ;
-        debug-message "  $(full-cmd) aborted with " ;
-        debug-message "  $(result[1])" ;
+        local full-cmd = "import sys; sys.stderr = sys.stdout; import numpy; print(numpy.get_include())" ;
+        local full-cmd = $(interpreter-cmd)" -c \"$(full-cmd)\"" ;
+        debug-message "running command '$(full-cmd)'" ;
+        local result = [ SHELL $(full-cmd) : strip-eol : exit-status ] ;
+        if $(result[2]) = 0
+        {
+            .numpy = true ;
+            .numpy-include = $(result[1]) ;
+            debug-message "NumPy enabled" ;
+        }
+        else
+        {
+            debug-message "NumPy disabled. Reason:" ;
+            debug-message "  $(full-cmd) aborted with " ;
+            debug-message "  $(result[1])" ;
+        }
     }
 
     #