Clock does not recognise fmt-10.0.0 format specifier

[bradrn]

Version 10.0.0 of fmt introduced support for padding seconds, minutes and hours (so e.g. producing output like 1 rather than 01). I have tested that this works on my system by compiling and running the following C++ program:

#include <fmt/chrono.h>

int main() {
    auto t = tm();
    t.tm_year = 2010 - 1900;
    t.tm_mon = 7;
    t.tm_mday = 4;
    t.tm_hour = 1;
    t.tm_min = 15;
    t.tm_sec = 58;
    fmt::print("{:%_I}", t);
    return 0;
}

As expected, this prints 1 (with an initial space).

However, when I try using the same format string with waybar, it simply produces the literal text %_I:

My clock configuration is as follows:

    "clock": {
        "tooltip-format": "<tt>{calendar}</tt>",
        "format": "{:%_I}",
        "calendar": {
            "mode": "month",
            "on-scroll": 1,
            "weeks-pos": "left",
            "format": {
                // omitted for brevity
            }
        },
        "actions":  {
                // omitted for brevity
        }
    },

Note that the format string is exactly the same as that used in the C++ program above.

For reference, I am using EndeavourOS (so basically Arch Linux), with waybar-0.9.20-2 and fmt-10.0.0-1. My compositor is Sway, though I presume that makes no difference.

[LukashonakV]

Hi @bradrn , As far as I know, the waybar now doesn't support fmt 10 version. But I might be wrong. Anyway I'll check it, once have a time. My assumption is because arch users recently raised questions about missing fmt 10 library in chain with waybar. See #2353
Thank you.

[bradrn]

waybar now doesn't support fmt 10 version

Insofar as I’m aware, it shouldn’t matter, since the call to fmt::print (or whichever function is used by waybar) should be the same either way. It certainly works on my machine with fmt-10.0.0 — it’s just that the new format specifiers introduced by that version don’t seem to work.

[LukashonakV]

waybar now doesn't support fmt 10 version

Insofar as I’m aware, it shouldn’t matter, since the call to fmt::print (or whichever function is used by waybar) should be the same either way. It certainly works on my machine with fmt-10.0.0 — it’s just that the new format specifiers introduced by that version don’t seem to work.

Clock module uses the exact fmt library. So.. it's definitely a strange case when you are able to use fmt10 ... but clock component shows unexpected results.. .OK, let me check...

[bradrn]

I probably should have mentioned that other format strings show the expected results, e.g.:

This is with {:%a %Od %b,\t%I:%M %p}.

[DigitalDragon64]

Probably related to this: Since my last system update (waybar and fmt were both updated) the decimal points of the seconds are printed, when just giving the format specifier %S.

Edit: %.0S is not recognized as a format and will be printed as it is.

[ti-mo]

@DigitalDragon64 Same, created an issue for it here: #2378.

[LukashonakV]

Hi @bradrn , I found your conversation fmtlib/fmt#3516
Finally, I built waybar with dependency fmt = 10.0.0. There is an issue: test/chrono-test.cc
format:
EXPECT_EQ(fmt::format("{:%_OI,%_OH,%_OM,%_OS}", tm), " 1, 1, 2, 3");
EXPECT_EQ(fmt::format("{:%-OI,%-OH,%-OM,%-OS}", tm), "1,1,2,3");
doesn't work. At the same time, I see that both merge requets were approved and now are part of the vmt:10 version according to release notes. See fmt 10 RN - row Improved validation of format specifiers for std::chrono::duration (https://github.com/fmtlib/fmt/issues/3219, https://github.com/fmtlib/fmt/pull/3232). Thanks [@ShawnZhong (Shawn Zhong)](https://github.com/ShawnZhong).
There's the same issue, which was waiting for fmt 10 -> #1469
So it actually looks like it needs an issue to be raised to fmt upstream.

I'll do additional investigation. If it won't bring luck, I create an issue to upstream

[bradrn]

So it actually looks like it needs an issue to be raised to fmt upstream.

Except that exactly the same format string works when I directly use my version of fmt (see the test program above), but doesn’t work when I use it with waybar. So this can’t be an issue with fmt.

[LukashonakV]

@bradrn, Waybar uses date features like date::zoned_time. According cpp reference now it included into C++20 standard. I've just checked: fmt doesn't work with date::zoned_time. In the same time pure sys_time timpoint works well with fmt.
I'll create an issue to fmt to extend glibc extension on the whole chrono library including TZ API.

Upd: created issue fmtlib/fmt#3572

[bradrn]

Ah, that makes sense! Thanks for looking into this @LukashonakV.