Fixes https://github.com/regebro/tzlocal/issues/127 by adding a break to the while-loop that checks for valid paths from a simlink from /etc/localtime. The behavior of the loop is to check for valid files from the top down like this:

Example behavior with latest release and /etc/localtime -> /usr/share/zoneinfo/Etc/UTC

/usr/share/zoneinfo/Etc/UTC usr/share/zoneinfo/Etc/UTC share/zoneinfo/Etc/UTC zoneinfo/Etc/UTC Etc/UTC UTC

Creates an invalid configuration ('Etc/UTC' and 'UTC' don't match) because both '/usr/share/zoneinfo/Etc/UTC' and '/usr/share/zoneinfo/UTC' exist and are valid configurations:

{'/etc/sysconfig/clock': 'Etc/UTC', '/etc/localtime is a symlink to': 'UTC'}

With the while loop breaking on the first valid configuration, the desired behavior is realized:

/usr/share/zoneinfo/Etc/UTC usr/share/zoneinfo/Etc/UTC share/zoneinfo/Etc/UTC zoneinfo/Etc/UTC Etc/UTC {'/etc/sysconfig/clock': 'Etc/UTC', '/etc/localtime is a symlink to': 'Etc/UTC'}

Adding the break does not affect the opposite scenario, where the simlink points to /usr/share/zoneinfo/UTC, as the first valid config will still be 'UTC'.

tests pass:

coverage: platform linux, python 3.8.10-final-0 Name Stmts Miss Cover

tzlocal/init.py 4 0 100% tzlocal/unix.py 116 0 100% tzlocal/utils.py 57 1 98% tzlocal/win32.py 69 1 99% tzlocal/windows_tz.py 3 0 100%

TOTAL 249 2 99%

My timezone (CET-1) is not able to express as Continent/City. It would be only true in the time between End of October and End of March.

There is no timezone that supports them anytime.

Even more, if I set Etc/CET it does use DST even if not expressed.

I just ran into an issue where on my local machine get_localzone() returns a _PytzShimTimezone() wrapping a ZoneInfo() and providing the unwrap_shim() method, but in an Alpine Docker it returns a datetime.timezone object which does not have that method.

I've now started to write a wrapper along the lines of

def get_local_tzinfo() -> ZoneInfo:
    with warnings.catch_warnings():
        tz = get_localzone()
    if hasattr(tz, "unwrap_shim"):
        tz = tz.unwrap_shim()
    elif isinstance(tz, timezone) and tz == timezone.utc:
        tz = ZoneInfo("Etc/UTC")
    return tz

or thought maybe just

def get_local_tzinfo() -> ZoneInfo:
    zone_name = get_localzone_name()
    if zone_name is None:
        zone_name = "Etc/UTC"
    return ZoneInfo(zone_name)

but felt dirty doing so and am now wondering whether I'm doing something wrong or whether get_localzone() should always return the same type?

Python and tzlocal version: tzlocal version 4.2 Python version Python 3.8.5

OS info: NAME="Amazon Linux" VERSION="2" ID="amzn" ID_LIKE="centos rhel fedora" VERSION_ID="2" PRETTY_NAME="Amazon Linux 2" ANSI_COLOR="0;33" CPE_NAME="cpe:2.3:o:amazon:amazon_linux:2" HOME_URL="https://amazonlinux.com/"

Stack trace:

Python 3.8.5 (default, Feb 18 2021, 01:24:20) [GCC 7.3.1 20180712 (Red Hat 7.3.1-12)] on linux Type "help", "copyright", "credits" or "license" for more information.

import tzlocal l=tzlocal.get_localzone() Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.8/site-packages/tzlocal/unix.py", line 203, in get_localzone _cache_tz = _get_localzone() File "/usr/local/lib/python3.8/site-packages/tzlocal/unix.py", line 165, in _get_localzone tzname = _get_localzone_name(_root) File "/usr/local/lib/python3.8/site-packages/tzlocal/unix.py", line 144, in _get_localzone_name raise utils.ZoneInfoNotFoundError(message) tzlocal.utils.ZoneInfoNotFoundError: 'Multiple conflicting time zone configurations found:\n/etc/sysconfig/clock: Etc/UTC\n/etc/localtime is a symlink to: UTC\nFix the configuration, or set the time zone in a TZ environment variable.\n'

/etc/localtime link:

ll /etc/localtime lrwxrwxrwx 1 root root 27 Apr 5 00:09 /etc/localtime -> /usr/share/zoneinfo/Etc/UTC

Etc/UTC is not a simlink: ll /usr/share/zoneinfo/Etc/UTC -rw-r--r-- 8 root root 127 Feb 11 19:04 /usr/share/zoneinfo/Etc/UTC

and contents of clock file:

cat /etc/sysconfig/clock ZONE="Etc/UTC" UTC="true"

When ZONE is set to "Etc/UTC" the stack trace appears. When it's set to just "UTC" tzlocal appears to be fine with it.