diff --git a/pygbag/__init__.py b/pygbag/__init__.py
index 53db400..9d8f720 100644
--- a/pygbag/__init__.py
+++ b/pygbag/__init__.py
@@ -7,7 +7,7 @@
 
 from pathlib import Path
 
-__version__ = "0.8.3"
+__version__ = "0.8.4"
 
 # hack to test git cdn build without upgrading pygbag
 # beware can have side effects when file packager behaviour must change !
diff --git a/pygbag/support/cross/__EMSCRIPTEN__.py b/pygbag/support/cross/__EMSCRIPTEN__.py
index b77669d..6f64a07 100644
--- a/pygbag/support/cross/__EMSCRIPTEN__.py
+++ b/pygbag/support/cross/__EMSCRIPTEN__.py
@@ -26,9 +26,9 @@ def shed_yield():
 
 # those  __dunder__ are usually the same used in C conventions.
 
-#try:
+# try:
 #    __UPY__
-#except:
+# except:
 #    if hasattr(sys.implementation, "_mpy"):
 #        builtins.__UPY__ = this
 #    else:
diff --git a/pygbag/support/cross/aio/__init__.py b/pygbag/support/cross/aio/__init__.py
index 4ff25ad..896ecfc 100644
--- a/pygbag/support/cross/aio/__init__.py
+++ b/pygbag/support/cross/aio/__init__.py
@@ -3,7 +3,6 @@
 import inspect
 
 
-
 DEBUG = True
 NICE = 0.010
 
@@ -40,6 +39,7 @@ def pdb(*argv):
     from .filelike import *
 else:
     import utime
+
     time_time = utime.ticks_ms
 
 
@@ -152,8 +152,11 @@ def overloaded(i, *attrs):
 __run__ = run
 
 if __UPY__:
-    def _set_running_loop(l):pass
-    sys.modules['asyncio.events'] = aio
+
+    def _set_running_loop(l):
+        pass
+
+    sys.modules["asyncio.events"] = aio
     aio.get_running_loop = aio.get_event_loop
     events = aio
 else:
@@ -170,8 +173,8 @@ def _set_running_loop(l):pass
     loop = get_event_loop()
 
 
-#import asyncio.events
-#asyncio.events._set_running_loop(loop)
+# import asyncio.events
+# asyncio.events._set_running_loop(loop)
 _set_running_loop(loop)
 
 
diff --git a/pygbag/support/cross/aio/cross.py b/pygbag/support/cross/aio/cross.py
index 3568995..e40b3d7 100644
--- a/pygbag/support/cross/aio/cross.py
+++ b/pygbag/support/cross/aio/cross.py
@@ -29,7 +29,6 @@ def print_exception(e, out=sys.stderr, **kw):
         del print_exception
 
 
-
 if not defined("__WASM__"):
     try:
         # that sym cannot be overloaded in the simulator
@@ -53,7 +52,6 @@ def print_exception(e, out=sys.stderr, **kw):
 define("__wasi__", __wasi__)
 
 
-
 # this *is* the cpython way
 if hasattr(sys, "getandroidapilevel"):
     platform_impl = defined("__ANDROID__")
@@ -133,9 +131,6 @@ def print_exception(e, out=sys.stderr, **kw):
     sys.modules["platform"] = platform_impl
 
 
-
-
-
 if not __UPY__:
     # setup exception display with same syntax as upy
     import traceback
diff --git a/pygbag/support/cross/aio/filelike.py b/pygbag/support/cross/aio/filelike.py
index 2e1d320..20d2ec2 100644
--- a/pygbag/support/cross/aio/filelike.py
+++ b/pygbag/support/cross/aio/filelike.py
@@ -3,6 +3,7 @@
 
 if not __UPY__:
     import socket
+
     socket.setdefaulttimeout(0.0)
 else:
     print("7: usocket implementation required")
@@ -11,7 +12,6 @@
 import os  # unlink
 
 
-
 import aio
 import platform
 
@@ -58,7 +58,6 @@ def mktemp(suffix=""):
 
 class fopen:
     if __WASM__ and hasattr(platform, "ffi"):
-
         flags = platform.ffi(
             {
                 "redirect": "follow",
diff --git a/pygbag/support/cross/aio/toplevel.py b/pygbag/support/cross/aio/toplevel.py
index c1a9340..211983d 100644
--- a/pygbag/support/cross/aio/toplevel.py
+++ b/pygbag/support/cross/aio/toplevel.py
@@ -17,7 +17,6 @@
     embed = False
 
 if not __UPY__:
-
     import code
 
     def install(pkg_file, sconf=None):
@@ -50,7 +49,6 @@ def install(pkg_file, sconf=None):
             pdb(f"49: cannot install {pkg_file}")
             sys.print_exception(ex)
 
-
     async def get_repo_pkg(pkg_file, pkg, resume, ex):
         global HISTORY
 
@@ -107,7 +105,6 @@ async def get_repo_pkg(pkg_file, pkg, resume, ex):
                 sys.print_exception(ex, limit=-1)
         return None
 
-
     class AsyncInteractiveConsole(code.InteractiveConsole):
         instance = None
         console = None
@@ -317,5 +314,6 @@ async def start_toplevel(cls, shell, console=True, ns="__main__"):
                 cls.start_console(shell, ns=ns)
 
 else:
+
     class AsyncInteractiveConsole:
         ...
diff --git a/pygbag/support/pythonrc.py b/pygbag/support/pythonrc.py
index 457d16f..689a414 100644
--- a/pygbag/support/pythonrc.py
+++ b/pygbag/support/pythonrc.py
@@ -196,7 +196,7 @@ def dump_code():
 
     aio.cross.simulator = False
     sys.argv.clear()
-    sys.argv.extend( PyConfig.pop("argv", []) )
+    sys.argv.extend(PyConfig.pop("argv", []))
 
 
 except Exception as e:
@@ -206,7 +206,7 @@ def dump_code():
     PyConfig["dev_mode"] = 1
     PyConfig["run_filename"] = "main.py"
 
-# TODO: use location of python js module.
+    # TODO: use location of python js module.
     if __UPY__:
         PyConfig["executable"] = "upy"
     else:
@@ -843,12 +843,12 @@ async def exec(cls, sub, **env):
 # end shell
 
 
-
 if __UPY__:
     import types
+
     class SimpleNamespace:
         def __init__(self, **kwargs):
-            for k,v in kwargs.items():
+            for k, v in kwargs.items():
                 setattr(self, k, v)
 
         def __repr__(self):
@@ -858,6 +858,7 @@ def __repr__(self):
 
         def __eq__(self, other):
             return self.__dict__ == other.__dict__
+
     types.SimpleNamespace = SimpleNamespace
 else:
     from types import SimpleNamespace
@@ -1015,9 +1016,9 @@ def File(path):
         pdb("1010: missing os.umask")
         pdb("1011: missing zipfile")
 
-
     import aio.toplevel
-    #import ast
+
+    # import ast
     from pathlib import Path
 
     class TopLevel_async_handler(aio.toplevel.AsyncInteractiveConsole):
@@ -1085,6 +1086,7 @@ def eval(self, source):
         @classmethod
         def scan_imports(cls, code, filename, load_try=False, hint=""):
             import ast
+
             required = []
             try:
                 root = ast.parse(code, filename)
diff --git a/pygbag/testserver.py b/pygbag/testserver.py
index c95f0f2..ca0a723 100644
--- a/pygbag/testserver.py
+++ b/pygbag/testserver.py
@@ -36,9 +36,9 @@
 CACHE = None
 
 # does not support {x=}
-#try:
+# try:
 #    from future_fstrings import fstring_decode
-#except:
+# except:
 fstring_decode = False
 
 
@@ -85,9 +85,11 @@ def do_HEAD(self):
     def send_head(self):
         global VERB, CDN, PROXY, BCDN, BPROXY, AUTO_REBUILD
         path = self.translate_path(self.path)
-        print(f"""
+        print(
+            f"""
 
-{self.path=} {path=}""")
+{self.path=} {path=}"""
+        )
 
         f = None
         if os.path.isdir(path):
diff --git a/scripts/build-rootfs.sh b/scripts/build-rootfs.sh
index 8d9fc38..bffa36c 100755
--- a/scripts/build-rootfs.sh
+++ b/scripts/build-rootfs.sh
@@ -117,6 +117,10 @@ import tty
 # cffi
 import copy
 
+# datetime 
+import datetime
+import _strptime
+
 # numpy
 import secrets
 
diff --git a/static/pythons.js b/static/pythons.js
index 31c643b..380ac0d 100644
--- a/static/pythons.js
+++ b/static/pythons.js
@@ -2264,12 +2264,13 @@ console.warn("TODO: merge/replace location options over script options")
     }
 
     // resolve python executable, cmdline first then script
-    var pystr = "cpython"
+    const default_version = "3.11"
+    var pystr = "cpython" + default_version
 
-    if (vm.cpy_argv.length && vm.cpy_argv[0].search('py')>=0) {
+    if (vm.cpy_argv.length && (vm.cpy_argv[0].search('py')>=0)) {
         pystr = vm.cpy_argv[0]
     } else {
-        if (cfg.python.search('py')>=0) {
+        if (cfg.python && (cfg.python.search('py')>=0)) {
             pystr = cfg.python
         }
         // fallback to cpython
@@ -2277,7 +2278,7 @@ console.warn("TODO: merge/replace location options over script options")
 
     if (pystr.search('cpython3')>=0) {
         vm.script.interpreter = "cpython"
-        config.PYBUILD = pystr.substr(7) || "3.11"
+        config.PYBUILD = pystr.substr(7) || default_version
     } else {
         if (pystr.search('python3')>=0) {
             vm.script.interpreter = "python"
@@ -2288,7 +2289,7 @@ console.warn("TODO: merge/replace location options over script options")
                 config.PYBUILD = pystr.substr(4) || "3.4"
             } else {
                 vm.script.interpreter = config.python || "cpython"
-                config.PYBUILD = pystr.substr(7) || "3.11"
+                config.PYBUILD = pystr.substr(7) || default_version
             }
         }
     }