[R] strptime() keeps emitting warnings after establishing a handler with tryCatch()

[Rui Barradas]

Hello,

I cannot reproduce this behavior and, as documented, the posted code 
doesn't issue warnings due to a wrong timezone but I'm running


sessionInfo()
R version 4.0.3 (2020-10-10)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 20.04.1 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.9.0

locale:
  [1] LC_CTYPE=pt_PT.UTF-8       LC_NUMERIC=C
  [3] LC_TIME=pt_PT.UTF-8        LC_COLLATE=pt_PT.UTF-8
  [5] LC_MONETARY=pt_PT.UTF-8    LC_MESSAGES=pt_PT.UTF-8
  [7] LC_PAPER=pt_PT.UTF-8       LC_NAME=C
  [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=pt_PT.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_4.0.3


Hope this helps,

Rui Barradas

Às 23:55 de 31/10/20, David Kepplinger escreveu:
> Dear list members,
> 
> I have come about a peculiar behavior in R (4.0.2) which I would
> describe as a bug.
> On macOS, where `strptime()` raises a warning for invalid timezone
> identifiers, the following code will continue to raise the original
> warning with every subsequent call to `strptime()`:
> 
> ```
> # attach a handler for warnings for this call only:
> tryCatch(strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz =
> 'Wrong Timezone!'),
>                    warning = function (w) { stop("Error") })
> # but every subsequent call will emit the original warning ("unknown
> timezone 'Wrong Timezone!'")
> strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz = 'Europe/Vienna')
> strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz = 'GMT')
> ```
> 
> The output of the code above in R 4.0.2 on macOS is:
> 
>> tryCatch(strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz = 'Wrong Timezone!'),
> +                   warning = function (w) { stop("Error") })
> Error in value[[3L]](cond) : Error
>>
>> strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz = 'Europe/Vienna')
> [1] "2020-10-31 18:30:00 CET"
> Warning message:
> In strptime("2020-10-31 18:30", format = "%Y-%m-%d %H:%M", tz =
> "Europe/Vienna") :
>    unknown timezone 'Wrong Timezone!'
>> strptime('2020-10-31 18:30', format = '%Y-%m-%d %H:%M', tz = 'GMT')
> [1] "2020-10-31 18:30:00 GMT"
> Warning messages:
> 1: In strptime("2020-10-31 18:30", format = "%Y-%m-%d %H:%M", tz = "GMT") :
>    unknown timezone 'Wrong Timezone!'
> 
> The corresponding R session info is:
> 
>> sessionInfo()
> R version 4.0.2 Patched (2020-07-13 r78838)
> Platform: x86_64-apple-darwin17.0 (64-bit)
> Running under: macOS Catalina 10.15.7
> 
> Matrix products: default
> BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
> LAPACK: /Library/Frameworks/R.framework/Versions/4.0/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_4.0.2
> 
> 
> I get the same odd behavior when attaching calling handlers with
> `withCallingHandlers()`.
> On RHEL 7 and Cent OS 6, which both don't issue warnings for invalid
> timezones, the above code works.
> 
> I don't see anything wrong with the code itself, but maybe I am
> missing something. Any input would be appreciated.
> 
> Best wishes,
> David
> 
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