[log][v2] How to convert log time to local time?

[ayangweb]

Currently using UseLocal is not local time? How do I convert them correctly?

...
.plugin(
    tauri_plugin_log::Builder::new()
        .timezone_strategy(TimezoneStrategy::UseLocal)
        .build(),
)

Log time:

Local time:

[Legend-Master]

TimezoneStrategy::UseLocal works for me here on Windows 10

I wonder if error you got is because of this errored out and fall backed to use UTC time instead, do you mind trying time-rs's time::OffsetDateTime::now_local() and see it works?

plugins-workspace/plugins/log/src/lib.rs

Line 158 in 36207a9

OffsetDateTime::now_local().unwrap_or_else(|_| OffsetDateTime::now_utc())

[ayangweb]

Also wrong

[Legend-Master]

Then it's probably a bug in time-rs, I recommend you open a bug report there (I don't have a mac device so I can't help much here)

[ayangweb]

@Legend-Master Hey👋, there's a reply. time-rs/time#713 (comment)

[Legend-Master]

Oh well, after some digging, it seems like you need TZ (stands for Time Zone) environment variable on unix systems to get the time zone, but getting the environment variable is not thread safe, so time just disabled this on all multi-threaded usages, chrono seems to use std::env::var which has a lock internally but it's only thread safe if there're no C calls to modify the environment variable

Not sure what we can do here, maybe switch to chrono?

Also see time-rs/time#293 (comment)

[jhpratt]

Incidentally, the last I checked chrono's behavior is unsound as well, just in slightly fewer situations. Even relying on only the standard library has been demonstrated to be unsound in extreme situations.

For what it's worth I am actively investigating a potential solution to make this work in multi-threaded situations on Unix while remaining sound and having the expected behavior in most cases. I think it's workable, but I should know for sure this coming week.

[ayangweb]

@Legend-Master @jhpratt Ok, thank you both, I won't test chrono then, looking forward to you guys solving this problem!

[Legend-Master]

I believe this is fixed by time v0.3.37 now, thanks @jhpratt!

Obtaining the system UTC offset on Unix-like systems should now succeed when multi-threaded. However, if the TZ environment variable is altered, the program will not be aware of this until time::util::refresh_tz or time::util::refresh_tz_unchecked is called. refresh_tz has the same soundness requirements as obtaining the system UTC offset previously did, with the requirements still being automatically enforced. refresh_tz_unchecked does not enforce these requirements at the expense of being unsafe. Most programs should not need to call either function.

Due to this change, the time::util::local_offset module has been deprecated in its entirety. The get_soundness and set_soundness functions are now no-ops.

Note that while calls should succeed, success is not guaranteed in any situation. Downstream users should always be prepared to handle the error case.