make sure lib/python*/lib-dynload exists in Python installation (fixes …

…#1957)

easybuild/easyblocks/p/python.py

@@ -279,6 +279,21 @@ def install_step(self):
         if self.cfg['ebpythonprefixes']:
             write_file(os.path.join(self.installdir, self.pythonpath, 'sitecustomize.py'), SITECUSTOMIZE)
 
+        # symlink lib/python*/lib-dynload to lib64/python*/lib-dynload if it doesn't exist;
+        # see https://github.com/easybuilders/easybuild-easyblocks/issues/1957
+        lib_dynload = 'lib-dynload'
+        lib_dynload_path = os.path.join(self.installdir, 'lib', 'python%s' % self.pyshortver, lib_dynload)
+        if not os.path.exists(lib_dynload_path):
+            lib64_dynload_path = os.path.join(self.installdir, 'lib64', 'python%s' % self.pyshortver, lib_dynload)
+            if os.path.exists(lib64_dynload_path):
+                lib_dynload_parent = os.path.dirname(lib_dynload_path)
+                mkdir(lib_dynload_parent, parents=True)
+                cwd = change_dir(lib_dynload_parent)
+                # use relative path as target, to avoid hardcoding path to install directory
+                target_lib_dynload = os.path.join('..', '..', 'lib64', 'python%s' % self.pyshortver, lib_dynload)
+                symlink(target_lib_dynload, lib_dynload)
+                change_dir(cwd)
+
     def sanity_check_step(self):
         """Custom sanity check for Python."""
 
@@ -313,7 +328,7 @@ def sanity_check_step(self):
         pyver = 'python' + self.pyshortver
         custom_paths = {
             'files': [os.path.join('bin', pyver), os.path.join('lib', 'lib' + pyver + abiflags + '.' + shlib_ext)],
-            'dirs': [os.path.join('include', pyver + abiflags), os.path.join('lib', pyver)],
+            'dirs': [os.path.join('include', pyver + abiflags), os.path.join('lib', pyver, 'lib-dynload')],
         }
 
         # cleanup