R help - Sep 2025 - `install.packages()` and https proxy with R 4.5

Hi all,

I work from a Windows 11 environment behind a firewall, and I require proxy
settings to reach the (private) R package repository I work with.
Using R 4.4 I used to set the environment variable "https_proxy" which
led
to e.g. "install.packages()" to work just fine.

I recently upgraded vom R version 4.4.2 to 4.5.1, and I find that the proxy
settings seem to be not respected anymore: I get an HTTP 401 error when
using `install.packages()`, while installing packages with the package
{pak} seems to work just fine. Switching the download method via the
install.packages argument `method` to "curl" also seems to do the
trick
(although that seems to introduce other problems).
Could it be that the default method (libcurl as far as I know) lost the
ability to respect the "https_proxy" environment variable? I find the
docs
of `install.packages()` and `download.file()` still suggest that this
should be working.

It seems to be that this is a bug in 4.5.1 but I wanted this mailing list's
opinion before opening a ticket or taking similar actions.

Best, Lukas

	[[alternative HTML version deleted]]

On Sun, Sep 28, 2025 at 10:45?AM Lukas Schneiderbauer
<lukas.schneiderbauer at gmail.com> wrote:
>
> Hi all,
>
> I work from a Windows 11 environment behind a firewall, and I require proxy
> settings to reach the (private) R package repository I work with.
> Using R 4.4 I used to set the environment variable "https_proxy"
which led
> to e.g. "install.packages()" to work just fine.

Maybe also try some of the other variables mentioned in
https://curl.se/libcurl/c/libcurl-env.html

On 30-09-2025 17:49, Jeroen Ooms wrote:
> On Sun, Sep 28, 2025 at 10:45?AM Lukas Schneiderbauer
> <lukas.schneiderbauer at gmail.com> wrote:
>>
>> Hi all,
>>
>> I work from a Windows 11 environment behind a firewall, and I require
proxy
>> settings to reach the (private) R package repository I work with.
>> Using R 4.4 I used to set the environment variable
"https_proxy" which led
>> to e.g. "install.packages()" to work just fine.
> 
> 
> Maybe also try some of the other variables mentioned in
> https://curl.se/libcurl/c/libcurl-env.html

That documentation mentions that 'http_proxy' is used for
'https://'
addresses. Is that variable also set?


I could also be that the proxy requires authentication with wininet this 
is often automatically done (I believe that was de default before R4.5). 
However, that doesn't explain why `method="curl"` would work. In
that
case you could try to set the proxy to `http_proxy=":@yourproxy"`.

HTH,
Jan


> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
https://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.