Make numerous improvements

- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands

third_party/python/Lib/os.py

@@ -21,14 +21,14 @@ and opendir), and leave all pathname manipulation to os.path
 (e.g., split and join).
 """
 
-#'
 import abc
-import sys, errno
+import sys
+import cosmo
+import errno
 import stat as st
 
 _names = sys.builtin_module_names
 
-# Note:  more names are added to __all__ later.
 __all__ = ["altsep", "curdir", "pardir", "sep", "pathsep", "linesep",
            "defpath", "name", "path", "devnull", "SEEK_SET", "SEEK_CUR",
            "SEEK_END", "fsencode", "fsdecode", "get_exec_path", "fdopen",
@@ -946,7 +946,10 @@ def popen(cmd, mode="r", buffering=-1):
         raise ValueError("invalid mode %r" % mode)
     if buffering == 0 or buffering is None:
         raise ValueError("popen() does not support unbuffered streams")
-    import subprocess, io
+    try:
+        import subprocess, io
+    except ImportError:
+        raise ImportError('cosmopolitan os.popen() requires manually yoinking subprocess')
     if mode == "r":
         proc = subprocess.Popen(cmd,
                                 shell=True,
@@ -1071,8 +1074,6 @@ if __name__ == 'PYOBJ.COM':
     F_TLOCK = 0
     F_ULOCK = 0
     GRND_NONBLOCK = 0
-    GRND_NORDRND = 0
-    GRND_NOSYSTEM = 0
     GRND_RANDOM = 0
     HAVE_FACCESSAT = 0
     HAVE_FCHMODAT = 0