Avoid that a system python is picked up. This replaces the need for d…

…efining this in the EasyConfig file, which was done fot pybind11 in GCCcore-9.3.0, but not done for the pybind11 in GCCcore-8.3.0

easybuild/easyblocks/p/pybind11.py

@@ -35,6 +35,7 @@
 from easybuild.tools.build_log import EasyBuildError
 from easybuild.tools.filetools import change_dir
 from easybuild.tools.run import run_cmd
+from easybuild.tools.modules import get_software_root
 
 
 class EB_pybind11(CMakePythonPackage):
@@ -54,6 +55,13 @@ def extra_options(extra_vars=None):
         extra_vars['download_dep_fail'][0] = True
         return extra_vars
 
+    def configure_step(self):
+        """Avoid that a system Python is picked up when a Python module is loaded"""
+        python_root = get_software_root('Python')
+        if python_root:
+            self.cfg.update('configopts', "-DPYTHON_EXECUTABLE=%s/bin/python" % python_root)
+        super(EB_pybind11, self).configure_step()
+
     def test_step(self):
         """Run pybind11 tests"""
         # always run tests