[Biopython] Local blast error on mac

[Anthony Underwood]

Running local blast+ through biopython on a mac I get the following error

Traceback (most recent call last):
 File "local_blast.py", line 31, in <module>
   local_blast_function.local_blast_function('gene_id_sequences.fasta', 'gene_id_blast_output.txt')
 File "/Users/sophia/legionella/scripts/local_blast_function.py", line 12, in local_blast_function
   stdout, stderr = blastp_cline()
 File "/Users/sophia/.pythonbrew/pythons/Python-2.7/lib/python2.7/site-packages/biopython-1.60-py2.7-macosx-10.6-x86_64.egg/Bio/Application/__init__.py", line 437, in __call__
   stdout_str, stderr_str)
Bio.Application.ApplicationError: Command '/usr/local/ncbi/blast/bin/blastp -out gene_id_blast_output.txt -outfmt 5 -query gene_id_sequences.fasta -db /Volumes/DataRAID/blast_databases/uniprot_sprot -evalue 0.001' returned non-zero exit status -11

If I run the command on its own

"/usr/local/ncbi/blast/bin/blastp -out gene_id_blast_output.txt -outfmt 5 -query gene_id_sequences.fasta -db /Volumes/DataRAID/blast_databases/uniprot_sprot -evalue 0.001"

This runs fine and it produces XML output. However through biopython it exits with a strange -11 error.

I've tried debugging the biopython code but to no avail-  no stderr is produced.

Does anybody have any suggestions as to what I might try?

Thanks

Anthony