The fu-shred binary is deprecated: it forwards all of its arguments to seqfu shred, which is the preferred command.
# Legacy
fu-shred -l 150 -s 50 genome.fa > reads.fq
# Preferred
seqfu shred -l 150 -s 50 genome.fa > reads.fq
Since SeqFu 1.30 the fu-readtope script has also been replaced, by seqfu shred --amplicon.