[R] GSL update fails configuration

[Rich Shepard]

Installed on this workstation is gsl-2.1-x86_64-1.

When I attempt to update the gls package it fails:
checking for gsl-config... /usr/bin/gsl-config
checking if GSL version >= 2.1... checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether the compiler supports GNU C... yes
checking whether gcc accepts -g... yes
checking for gcc option to enable C11 features... none needed
configure: error: Need GSL version >= 1.16
ERROR: configuration failed for package ‘gsl’

Since GSL-2.1 is found on line 2, why is there the error on line 11 that gsl
>= 1.16 is needed and not found?

What am I missing here?

Regards,

Rich