py25-hashlib fails to build

[simon@…]

$ sudo port install py25-hashlib
--->  Fetching py25-hashlib
--->  Verifying checksum(s) for py25-hashlib
--->  Extracting py25-hashlib
--->  Configuring py25-hashlib
--->  Building py25-hashlib
Error: Target org.macports.build returned: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_python_py25-hashlib/work/Python-2.5.4/Modules" && /opt/local/bin/python2.5 setup.py --no-user-cfg build " returned error 1
Command output: Traceback (most recent call last):
  File "setup.py", line 21, in <module>
    library_dirs = lib_dirs)]
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/core.py", line 125, in setup
    dist.parse_config_files()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/dist.py", line 366, in parse_config_files
    filenames = self.find_config_files()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/dist.py", line 329, in find_config_files
    check_environ()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/util.py", line 208, in check_environ
    os.environ['PLAT'] = get_platform()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/util.py", line 78, in get_platform
    cfgvars = get_config_vars()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/sysconfig.py", line 493, in get_config_vars
    func()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/distutils/sysconfig.py", line 375, in _init_posix
    elif map(int, cfg_target.split('.')) > map(int, cur_target.split('.')):
ValueError: invalid literal for int() with base 10: ''

Error: Status 1 encountered during processing.