deployments using older versions of foreign package produce spurious warnings

[kevinushey]

When rsconnect checks to see whether a package is available on CRAN, it does so by checking whether the latest-available version of that package is available on CRAN:

rsconnect/R/dependencies.R

Line 83 in 40c162b

repo.packages <- available.packages(contriburl = contrib.url(repos, type = "source"), type = "source")

However, the default filters (which define an inclusion / exclusion criteria for the packages returned by available.packages()) are left on. From ?available.packages:

Argument filters can be used to select which of the packages on the repositories are reported. It is called with its default value (NULL) by functions such as install.packages: this value corresponds to getOption("available_packages_filters") and to c("R_version", "OS_type", "subarch", "duplicates") if that is unset or set to NULL.

The built-in filters are

"R_version"
Exclude packages whose R version requirements are not met.

< ... snip ... >

The current source version of foreign requires R 4.0.0:

> db <- available.packages(type = "source")
> db["foreign", "Depends"]
[1] "R (>= 4.0.0)"

which implies that the aforementioned check would fail to see that foreign is a package available on CRAN, if the current version of R were older than 4.0.0.

Since this is ultimately just a warning, we could relax this check by removing the filters used by available.packages().

[jmcphers]

Does #432 address this?

[kevinushey]

Yes, I believe so!

[jmcphers]

Fixed by #432

[ronblum]

@jmcphers and/or @kevinushey I'm trying to reproduce this in the current CRAN version of rsconnect. Is the foreign package special to publishing to Connect, or is it just an example of a package that I would use in the Rmd?

[kevinushey]

This is specifically for any R package for which the latest-available source package requires R (>= 4.0.0); foreign is just one example of such a package: https://cran.r-project.org/web/packages/foreign/index.html

XML is another example: https://cran.r-project.org/web/packages/XML/index.html

[ronblum]

@kevinushey Thanks! I'll try out these packages with R 3.6.3 first.

[ronblum]

Verified by using foreign on 3.6.3. Deployment happened cleanly with no errors.

[All thanks to @kevinushey for walking me through the reprex, etc.]