fix travis CI error, hopefully
@@ -123,6 +123,7 @@ def read_if_vcf(params):
ref = None
aln = params.aln
fixed_pi = None
+ if hasattr(params, 'aln') and params.aln is not None:
if any([params.aln.lower().endswith(x) for x in ['.vcf', '.vcf.gz']]):
if not params.vcf_reference:
print("ERROR: a reference Fasta is required with VCF-format alignments")
