embedded_python_interpreter: fix python library path

Signed-off-by: Pawel Czarnecki <pczarnecki@antmicro.com>

dependency_support/embedded_python_interpreter/print_libpython_path.py

@@ -23,4 +23,13 @@
     for pv in ('LIBDIR', 'LIBPL')
 ]
 
+if 'rules_hdl_cpython' in config_vars['prefix']:
+    # Hack: Work around broken library paths in the hermetic Python toolchain.
+    # It reports that the library path is an absolute path like
+    #
+    #   /install/lib/libpython3.8.so
+    #
+    # This path doesn't exist. So we'll fix it here.
+    file_paths = [path.replace('/install', config_vars['prefix']) for path in file_paths]
+
 print(list(filter(os.path.exists, file_paths))[0])