I was running bowtie2-build and encountered the following error. Thanks for help!
bowtie2-build final.contigs.fa final.contigs
Input files DNA, FASTA:
Building a SMALL index
Reading reference sizes
Could not open index file for writing: "final.contigs.3.bt2"
Please make sure the directory exists and that permissions allow writing by Bowtie.
Time reading reference sizes: 00:00:00
Total time for call to driver() for forward index: 00:00:00
Error: Encountered internal Bowtie 2 exception (#1)