CRAN’s Rust versions

The build machines of CRAN do not have coordinated versions of Rust. The minimum Rust version of CRAN can dictate the crates and features extendr-powered packages can use (if you plan on distributing on CRAN).

The below table reports CRAN versions per check flavor based on the check results of the extendr package {fio}.

library(rvest)

check_links <- "https://cran.r-project.org/web/checks/check_results_fio.html" |> 
  read_html() |> 
  html_node(".container") |> 
  html_nodes("a") |> 
  html_attr("href") 

check_links <- unique(check_links[grepl("^https://", check_links)])

install_logs <- gsub(
  "00check.html",
  "00install.html",
  check_links
)

extract_semver <- function(ver) {
  if (grepl("\\d+\\.\\d+(\\.\\d+)?", ver)) {
    sub(".*?(\\d+\\.\\d+(\\.\\d+)?).*", "\\1", ver)
  } else {
    NA
  }
}

versions <- lapply(install_logs, function(.log) {
  lns <- readLines(.log)
  rust_version <- extract_semver(lns[grepl("^Using rustc", lns)])
  cargo_version <- extract_semver(lns[grepl("^Using cargo", lns)])
  data.frame(rustc = rust_version, cargo = cargo_version)
})


# get all of the flavors
flavor <- dirname(
  gsub("https://www.r-project.org/nosvn/r.check/", "", tolower(install_logs))
)

res <- cbind(
  "Check flavor" = flavor,
  do.call(rbind.data.frame, versions)
) |> 
  dplyr::mutate(rustc = numeric_version(rustc), cargo = numeric_version(cargo)) |> 
  dplyr::arrange(rustc)

CRAN’s MSRV is 1.81.0

Check flavor	rustc	cargo
r-devel-windows-x86_64	1.81.0	1.81.0
r-release-windows-x86_64	1.81.0	1.81.0
r-oldrel-windows-x86_64	1.81.0	1.81.0
r-release-macos-arm64	1.84.1	1.84.1
r-release-macos-x86_64	1.84.1	1.84.1
r-oldrel-macos-arm64	1.84.1	1.84.1
r-oldrel-macos-x86_64	1.84.1	1.84.1
r-oldrel-macos-arm64	1.84.1	1.84.1
r-oldrel-macos-x86_64	1.84.1	1.84.1
r-devel-linux-x86_64-debian-clang	1.85.0	1.85.0
r-devel-linux-x86_64-debian-gcc	1.85.0	1.85.0
r-patched-linux-x86_64	1.85.0	1.85.0
r-release-linux-x86_64	1.85.0	1.85.0
r-devel-linux-x86_64-fedora-clang	1.87.0	1.87.0
r-devel-linux-x86_64-fedora-gcc	1.87.0	1.87.0