PSA: R 4.1.x to 4.2.x CRAN not reachable. Observations and one fix

General
2

The default download method used for downloading files and installing packages on Windows was changed from wininet to libcurl in R 4.2.0. And wininet was apparently deprecated in R 4.1.1. Could that have been the cause?

Proxy settings are configured different between wininet and libcurl. wininet uses Internet Options and libcurl uses http[s]_proxy environment variables, which I guess would explain why the .Renviron solution worked.

CHANGES IN R 4.2.0

DEPRECATED AND DEFUNCT

  • On Windows, download.file(method = "wininet") no longer supports ‘⁠ftp://⁠’ URIs. (It is no longer the default method, which is "libcurl" and does.)

On Windows, the deprecated method = "wininet" now gives a warning for ‘⁠http://⁠’ and ‘⁠https://⁠’ URIs for both download.file() and url(). (It is no longer the default method.)

CHANGES IN R 4.1.1

DEPRECATED AND DEFUNCT

  • On Windows, method = "wininet" is deprecated for ‘⁠http://⁠’, ‘⁠https://⁠’ and ‘⁠ftp://⁠’ URIs for both download.file and url. (A warning is only given for ‘⁠ftp://⁠’.)

R: R News

Setting Proxies

For the Windows-only method "wininet", the ‘Internet Options’ of the system are used to choose proxies and so on; these are set in the Control Panel and are those used for system browsers.

For the "libcurl" and "curl" methods, proxies can be set via the environment variables http_proxy or ftp_proxy. See libcurl - programming tutorial for further details.

R: Download File from the Internet