SSL and-or Curl related errors in Windows package

[phjacobs]

Hello Tom et al.! I reached out to Nick about this and he suggested GitHub would be the better place to mention/ask about it.

The current version of zoon (0.65) won't work on Windows due to SSL/Curl related errors. You can see this in the check results on CRAN: https://cran.r-project.org/web/checks/check_results_zoon.html

Here is an actual example of the error "in the wild" from something I am working on:

Error in function (type, msg, asError = TRUE) : error:1407742E:SSL routines:SSL23_GET_SERVER_HELLO:tlsv1 alert protocol version
Traceback:

1. workflow(occurrence = LocalOccurrenceData(filename = "occurrence.csv",
   . occurrenceType = "presence/absence", columns = c(long = "Longitude",
   . lat = "Latitude", value = "presence")), covariate = LocalRaster("raster"),
   . process = Chain(Bootstrap, Crossvalidate(k = 5)), model = RandomForest,
   . output = Chain(PerformanceMeasures, VariableImportance, PrintMap(plot = TRUE)))
2. LapplyGetModule(occurrence.module, forceReproducible, e)
3. lapply(modules, function(x) {
   . GotModule <- GetModule(as.character(x$module), forceReproducible,
   . environment)
   . res <- c(x, func = GotModule, version = attr(GotModule, "version"))
   . return(res)
   . })
4. FUN(X[[i]], ...)
5. GetModule(as.character(x$module), forceReproducible, environment)
6. getURL(zoonURL, ssl.verifypeer = FALSE)
7. curlPerform(curl = curl, .opts = opts, .encoding = .encoding)
8. function (type, msg, asError = TRUE)
   . {
   . if (!is.character(type)) {
   . i = match(type, CURLcodeValues)
   . typeName = if (is.na(i))
   . character()
   . else names(CURLcodeValues)[i]
   . }
   . typeName = gsub("^CURLE_", "", typeName)
   . fun = (if (asError)
   . stop
   . else warning)
   . fun(structure(list(message = msg, call = sys.call()), class = c(typeName,
   . "GenericCurlError", "error", "condition")))
   . }(35L, "error:1407742E:SSL routines:SSL23_GET_SERVER_HELLO:tlsv1 alert protocol version",
   . TRUE)

I am no expert, but I wonder that there is something going on with either the openssl protocol on Windows, and/or whether changes to Github's handling of "raw" files (module list?) are to blame.

I was able to get zoon working on a Ubuntu machine after reinstalling the openssl library on the system AND also installing an archived version of the now deprecated SDMTools package.

[AugustT]

Here is a reproducible example

zoonURL <- "https://raw.githubusercontent.com/zoonproject/modules/master/R/Background.R"
RCurl::getURL(zoonURL, ssl.verifypeer = FALSE)