Tar test cases failing on systems with tape drives

[sunwire]

If $TAPE is set tar uses the tape drive instead of stdout as default and tests fail

===>  tar extension tests 

tmp.tar              : 29.84%   (  70.0 KiB =>   20.9 KiB, tmp.tzst)           
tmp.tzst            : 71680 bytes                                              
tar: /dev/nst0: Cannot open: No medium found
tar: Error is not recoverable: exiting now
tmp.tgz             : 0 bytes                                                  
tar: /dev/nst0: Cannot open: No medium found
tar: Error is not recoverable: exiting now
tmp.txz             : 0 bytes                                                  



tar: /dev/nst0: Cannot open: No medium found
tar: Error is not recoverable: exiting now
tmp.tlz4            : 0 bytes                                                  
zstd: tmp.t: unknown suffix (.zst/.tzst/.gz/.tgz/.lzma/.xz/.txz/.lz4/.tlz4 expected). Can't derive the output file name. Specify it with -o dstFileName. Ignoring.
zstd: tmp.tz: unknown suffix (.zst/.tzst/.gz/.tgz/.lzma/.xz/.txz/.lz4/.tlz4 expected). Can't derive the output file name. Specify it with -o dstFileName. Ignoring.
zstd: tmp.tzs: unknown suffix (.zst/.tzst/.gz/.tgz/.lzma/.xz/.txz/.lz4/.tlz4 expected). Can't derive the output file name. Specify it with -o dstFileName. Ignoring.