# No detail on errors in Shinyapps.io logs

I am getting this error message after deployment to Shinyapps.io:


2020-04-08T08:14:51.170999+00:00 shinyapps[2045921]: Error in value[3L] : Argument 2 must be length 23, not 138

2020-04-08T08:14:51.171001+00:00 shinyapps[2045921]: Calls: local ... tryCatch -> tryCatchList -> tryCatchOne ->

2020-04-08T08:14:51.171002+00:00 shinyapps[2045921]: Execution halted

I have tried as much as possible to replicate the package versions locally and I cannot replicate the error on my machine. I am not explicitly calling tryCatch anywhere in my code. So much is clear to me: somehwere a condition with length 23 is expected but 138 is received.

As I cannot replicate the error locally, it is very difficult to provide a reprex (if I could do that I would have probably solved the issue...), so my question is rather how to "force" the logs to produce a bit more information - like a call stack at least and which line in the code executed which function which apparently called tryCatch ... I have tried options(shiny.fullstacktrace = TRUE) but no luck.

Sorry for the lack of more clarity - any ideas much appreciated.
Thanks

1 Like

This is a hard one. Thank you for the full explanation!

Are you combining data that could possible have different lengths?

Try setting options(shiny.trace = TRUE).

#' \item{shiny.trace (defaults to FALSE)}{Print messages sent between the R server and the web
#' browser client to the R console. This is useful for debugging. Possible
#' values are "send" (only print messages sent to the client),
#' "recv" (only print messages received by the server), TRUE
#' (print all messages), or FALSE (default; don't print any of these
#' messages).}

Hopefully this will tell you what the input values were being set to so that you can try to replicate on your side.

Thanks @barret. The complication is also because I am in fact using Travis CI to automate the deployment process and apparently I couldn't replicate the exact package ecosystem (library I guess) on the Travis machine as on my own. Deployment from my machine using the UI and also using rsconnect::deployApp()was working fine.
In the end I managed to solve the problems with renv using this vignette as a guide: https://rstudio.github.io/renv/articles/ci.html