I've got a bit more information about this one. It seems like it (only? not
sure) appears when `TZ = "UTC"`, which is why I didn't see it
before on my
Mac, which defaults to `TZ = ""`. I think this is at least explainable
by
the fact that those "optional" fields aren't technically needed
when the
time zone is UTC.
I can reproduce this now on my personal Mac:
```
x <- as.POSIXlt(as.POSIXct("2013-01-31", tz =
"America/Chicago"))
Sys.setenv(TZ = "")
x[1] <- NA
x
#> [1] NA
x <- as.POSIXlt(as.POSIXct("2013-01-31", tz =
"America/Chicago"))
Sys.setenv(TZ = "America/New_York")
x[1] <- NA
x
#> [1] NA
x <- as.POSIXlt(as.POSIXct("2013-01-31", tz =
"America/Chicago"))
Sys.setenv(TZ = "UTC")
x[1] <- NA
#> Error in x[[n]][i] <- value[[n]] : replacement has length zero
x
#> [1] "2013-01-31 CST"
```
Here are `sessionInfo()` and `Sys.getenv("TZ")` outputs for 3 GitHub
Actions platforms where the bug exists (note they all set `TZ =
"UTC"`!):
Linux:
```
> sessionInfo()
R version 4.2.1 (2022-06-23)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.6 LTS
Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/openblas/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/libopenblasp-r0.2.20.so
locale:
[1] LC_CTYPE=C.UTF-8 LC_NUMERIC=C LC_TIME=C.UTF-8
[4] LC_COLLATE=C.UTF-8 LC_MONETARY=C.UTF-8 LC_MESSAGES=C.UTF-8
[7] LC_PAPER=C.UTF-8 LC_NAME=C LC_ADDRESS=C
[10] LC_TELEPHONE=C LC_MEASUREMENT=C.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] compiler_4.2.1
> Sys.getenv("TZ")
[1] "UTC"
```
Mac:
```
> sessionInfo()
R version 4.2.1 (2022-06-23)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Big Sur ... 10.16
Matrix products: default
BLAS:
/Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRblas.0.dylib
LAPACK:
/Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRlapack.dylib
locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] compiler_4.2.1
> Sys.getenv("TZ")
[1] "UTC"
```
Windows:
This is the best I can get you, sorry (remote worker issues), but note that
it does also say `tz UTC` like the others.
```
version R version 4.2.1 (2022-06-23 ucrt)
os Windows Server x64 (build 20348)
system x86_64, mingw32
ui RTerm
language (EN)
collate English_United States.utf8
ctype English_United States.utf8
tz UTC
date 2022-10-11
```
And here is my Mac where the bug doesn't show up by default because `TZ
""`:
```
> sessionInfo()
R version 4.2.1 (2022-06-23)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Big Sur ... 10.16
Matrix products: default
BLAS:
/Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRblas.0.dylib
LAPACK:
/Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRlapack.dylib
locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] compiler_4.2.1
> Sys.getenv("TZ")
[1] ""
> Sys.timezone()
[1] "America/New_York"
```
-Davis
On Thu, Oct 6, 2022 at 9:33 AM Davis Vaughan <davis at rstudio.com> wrote:
> Hi all,
>
> I have found another POSIXlt bug while I've been fiddling around with
it.
> This one only appears on specific OSes, because it has to do with the fact
> that the `gmtoff` field is optional, and isn't always used on all OSes.
It
> also doesn't seem to be specific to r-devel, I think it has been there
> awhile.
>
> Here is the bug:
>
> ```
> x <- as.POSIXlt(as.POSIXct("2013-01-31", tz =
"America/Chicago"))
>
> # Oh no!
> x[1] <- NA
> #> Error in x[[n]][i] <- value[[n]] : replacement has length zero
> ```
>
> If you look at the objects, you can see that `x` has a `gmtoff` field, but
> `NA` (when converted to POSIXlt, which is what `[<-.POSIXlt` does) does
not:
>
> ```
> unclass(x)
> #> $sec
> #> [1] 0
> #>
> #> $min
> #> [1] 0
> #>
> #> $hour
> #> [1] 0
> #>
> #> $mday
> #> [1] 31
> #>
> #> $mon
> #> [1] 0
> #>
> #> $year
> #> [1] 113
> #>
> #> $wday
> #> [1] 4
> #>
> #> $yday
> #> [1] 30
> #>
> #> $isdst
> #> [1] 0
> #>
> #> $zone
> #> [1] "CST"
> #>
> #> $gmtoff
> #> [1] -21600
> #>
> #> attr(,"tzone")
> #> [1] "America/Chicago" "CST"
"CDT"
>
> unclass(as.POSIXlt(NA))
> #> $sec
> #> [1] NA
> #>
> #> $min
> #> [1] NA
> #>
> #> $hour
> #> [1] NA
> #>
> #> $mday
> #> [1] NA
> #>
> #> $mon
> #> [1] NA
> #>
> #> $year
> #> [1] NA
> #>
> #> $wday
> #> [1] NA
> #>
> #> $yday
> #> [1] NA
> #>
> #> $isdst
> #> [1] -1
> #>
> #> attr(,"tzone")
> #> [1] "UTC"
> ```
>
> The problem seems to be that `[<-.POSIXlt` assumes that if the field was
> there in `x` then it must also be there in `value`:
>
>
https://github.com/wch/r-source/blob/e10a971dee6a0ab851279c183cc21954d66b3be4/src/library/base/R/datetime.R#L1303-L1304
>
> But this isn't the case for the `NA` value that was converted to
POSIXlt.
>
> I can't reproduce this on my personal Mac, but it affects the Linux,
Mac,
> and Windows machines we use for the lubridate CI checks through GitHub
> Actions.
>
> Thanks,
> Davis
>
[[alternative HTML version deleted]]