in reply to
Trying -- and failing -- to install modules from cpan
The following (from your output) may be a clue as to what is occurring (lines 13 and following):
Using Tar:/usr/bin/tar x1f "Chart-Gnuplot-0.17.tar":
List: tar -tf <archive-filename>
Extract: tar -xf <archive-filename>
Create: tar -cf <archive-filename> filenames...
Help: tar --help
Couldn't untar Chart-Gnuplot-0.17.tar
My guess would be that it is trying to use 'tar x1f filename.tar' to extract it, but that the version of tar on your system requires a '-' on options (thus, 'tar -xf filename.tar'). How to fix that, though, I am not sure (but hope others may be able to suggest).
Hope that helps.