Revert "Bump apscheduler from 3.10.1 to 3.10.4 (#2133)"

This reverts commit 2c42150799.

lib/tzlocal/utils.py

@@ -1,9 +1,9 @@
-import logging
+# -*- coding: utf-8 -*-
 import os
 import time
 import datetime
 import calendar
-import warnings
+import pytz_deprecation_shim as pds
 
 try:
     import zoneinfo  # pragma: no cover
@@ -12,7 +12,35 @@ except ImportError:
 
 from tzlocal import windows_tz
 
-log = logging.getLogger("tzlocal")
+
+class ZoneInfoNotFoundError(pds.UnknownTimeZoneError, zoneinfo.ZoneInfoNotFoundError):
+    """An exception derived from both pytz and zoneinfo
+
+    This exception will be trappable both by pytz expecting clients and
+    zoneinfo expecting clients.
+    """
+
+
+def get_system_offset():
+    """Get system's timezone offset using built-in library time.
+
+    For the Timezone constants (altzone, daylight, timezone, and tzname), the
+    value is determined by the timezone rules in effect at module load time or
+    the last time tzset() is called and may be incorrect for times in the past.
+
+    To keep compatibility with Windows, we're always importing time module here.
+    """
+
+    localtime = calendar.timegm(time.localtime())
+    gmtime = calendar.timegm(time.gmtime())
+    offset = gmtime - localtime
+    # We could get the localtime and gmtime on either side of a second switch
+    # so we check that the difference is less than one minute, because nobody
+    # has that small DST differences.
+    if abs(offset - time.altzone) < 60:
+        return -time.altzone  # pragma: no cover
+    else:
+        return -time.timezone  # pragma: no cover
 
 
 def get_tz_offset(tz):
@@ -20,27 +48,19 @@ def get_tz_offset(tz):
     return int(datetime.datetime.now(tz).utcoffset().total_seconds())
 
 
-def assert_tz_offset(tz, error=True):
+def assert_tz_offset(tz):
     """Assert that system's timezone offset equals to the timezone offset found.
 
     If they don't match, we probably have a misconfiguration, for example, an
-    incorrect timezone set in /etc/timezone file in systemd distributions.
-
-    If error is True, this method will raise a ValueError, otherwise it will
-    emit a warning.
-    """
-
+    incorrect timezone set in /etc/timezone file in systemd distributions."""
     tz_offset = get_tz_offset(tz)
-    system_offset = calendar.timegm(time.localtime()) - calendar.timegm(time.gmtime())
-    # No one has timezone offsets less than a minute, so this should be close enough:
-    if abs(tz_offset - system_offset) > 60:
+    system_offset = get_system_offset()
+    if tz_offset != system_offset:
         msg = (
             "Timezone offset does not match system offset: {} != {}. "
             "Please, check your config files."
         ).format(tz_offset, system_offset)
-        if error:
-            raise ValueError(msg)
-        warnings.warn(msg)
+        raise ValueError(msg)
 
 
 def _tz_name_from_env(tzenv=None):
@@ -50,8 +70,6 @@ def _tz_name_from_env(tzenv=None):
     if not tzenv:
         return None
 
-    log.debug(f"Found a TZ environment: {tzenv}")
-
     if tzenv[0] == ":":
         tzenv = tzenv[1:]
 
@@ -74,9 +92,6 @@ def _tz_name_from_env(tzenv=None):
             # Indeed
             return parts[-1]
 
-    log.debug("TZ does not contain a time zone name")
-    return None
-
 
 def _tz_from_env(tzenv=None):
     if tzenv is None:
@@ -97,16 +112,17 @@ def _tz_from_env(tzenv=None):
             # Nope, not a standard timezone name, just take the filename
             tzname = tzenv.split(os.sep)[-1]
         with open(tzenv, "rb") as tzfile:
-            return zoneinfo.ZoneInfo.from_file(tzfile, key=tzname)
+            zone = zoneinfo.ZoneInfo.from_file(tzfile, key=tzname)
+            return pds.wrap_zone(zone)
 
     # TZ must specify a zoneinfo zone.
     try:
-        tz = zoneinfo.ZoneInfo(tzenv)
+        tz = pds.timezone(tzenv)
         # That worked, so we return this:
         return tz
-    except zoneinfo.ZoneInfoNotFoundError:
+    except pds.UnknownTimeZoneError:
         # Nope, it's something like "PST4DST" etc, we can't handle that.
-        raise zoneinfo.ZoneInfoNotFoundError(
+        raise ZoneInfoNotFoundError(
             "tzlocal() does not support non-zoneinfo timezones like %s. \n"
-            "Please use a timezone in the form of Continent/City" % tzenv
+            "Please use a timezone in the form of Continent/City"
         ) from None