[R] Configure error: checking if libcurl supports https... no

[Rolf Turner]

I'm getting results from a package which differ from results that I got
a few weeks ago, and the only thing that I can think of that's changed
is the version of R (from 4.1.0 to 4.4.1).

So I wanted to install 4.1.0 and play around with that, to see if that
is indeed the explanation.  (If that is so, a whole new set of
questions would be raised, but let's leave that for the moment.)  I
downloaded the tarball and set about installing 4.1.0 from source.  But
the configure step threw an error, as given in the subject line of
this message.  The error went on:

> configure: error: libcurl >= 7.28.0 library and headers are required
> with support for https

A bit of web searching turned up the advice to re-install curl
using

    sudo apt-get install curl

but when I did that I was informed that:

> curl is already the newest version (7.68.0-1ubuntu2.6).

Has anyone got any *useful* advice?  If so, please present it
in very simple terms if you can.  (I am a Bear of Very Little Brain,
and long words bother me.)  A step-by-step recipe would be appreciated.

I'm running Ubuntu 20.04, with a Mate 1.24.0 desktop.

Grateful for any pearls of wisdom.

cheers,

Rolf Turner

P.S. The config.log file seems to be full of stuff relating to errors
from "openssl.c" but this is *way* beyond my pay grade.

R. T.

-- 
Honorary Research Fellow
Department of Statistics
University of Auckland
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