diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -114,6 +114,7 @@ def _safe_realpath(path):
     try:
         return realpath(path)
     except OSError:
+        # ignore error, e.g. if the current directory was removed
         return path
 
 if sys.executable:
@@ -182,7 +183,13 @@ def _get_default_scheme():
 def _getuserbase():
     env_base = os.environ.get("PYTHONUSERBASE", None)
     def joinuser(*args):
-        return os.path.expanduser(os.path.join(*args))
+        path = os.path.join(*args)
+        try:
+            return os.path.expanduser(path)
+        except KeyError:
+            # ignore pwd.getpwuid() error: the HOME environment variable is not
+            # set and the current user has not entry in /etc/passwd
+            pass
 
     # what about 'os2emx', 'riscos' ?
     if os.name == "nt":
@@ -485,6 +492,7 @@ def get_config_vars(*args):
             _init_non_posix(_CONFIG_VARS)
         if os.name == 'posix':
             _init_posix(_CONFIG_VARS)
+
         # Setting 'userbase' is done below the call to the
         # init function to enable using 'get_config_var' in
         # the init-function.