package/python-numpy: fixup npymath.ini for numpy extensions

In order to build the numpy distutils extension packages like
python-scipy, python-numba, it requires an explicit pkg-config
path fixup for npymath.ini.

This pkg-config path fixup would update the prefix path of
npymath.ini with actual target staging area where numpy core
was built, so that numpy distutils extension packages would
explicitly link this config path for their package environment.

Without this extension packages cannot find -lnpymath since
it uses host libraries (like libnpymath.a).

So, attach the post install staging hook with pkg-config
path fixup for npymath.ini.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/python-numpy/python-numpy.mk

@@ -34,6 +34,21 @@ define PYTHON_NUMPY_CONFIGURE_CMDS
 	echo "include_dirs = $(STAGING_DIR)/usr/include" >> $(@D)/site.cfg
 endef
 
+# Fixup the npymath.ini prefix path with actual target staging area where
+# numpy core was built. Without this, target builds using numpy distutils
+# extensions like python-scipy, python-numba cannot find -lnpymath since
+# it uses host libraries (like libnpymath.a).
+# So, the numpy distutils extension packages would explicitly link this
+# config path for their package environment.
+PYTHON_NUMPY_STAGING_DIR = $(STAGING_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages/numpy
+PYTHON_NUMPY_NPY_PKG_CONFIG_PATH=$(PYTHON_NUMPY_STAGING_DIR)/core/lib/npy-pkg-config
+define PYTHON_NUMPY_FIXUP_NPY_PKG_CONFIG_FILES
+	sed -e '/^pkgdir=/d' \
+	    -e '/^prefix=/i pkgdir=$(PYTHON_NUMPY_STAGING_DIR)/core' \
+	    -i $(PYTHON_NUMPY_NPY_PKG_CONFIG_PATH)/npymath.ini
+endef
+PYTHON_NUMPY_POST_INSTALL_STAGING_HOOKS += PYTHON_NUMPY_FIXUP_NPY_PKG_CONFIG_FILES
+
 # Some package may include few headers from NumPy, so let's install it
 # in the staging area.
 PYTHON_NUMPY_INSTALL_STAGING = YES