diff --git a/breakseq2/biopy/io/SV.py b/breakseq2/biopy/io/SV.py
index 629374c..4389059 100644
--- a/breakseq2/biopy/io/SV.py
+++ b/breakseq2/biopy/io/SV.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 
-import sys, os
+import sys, os, logging
 import Fasta
 import GFF
 
@@ -124,8 +124,13 @@ def get_flanks(self):
 
 
 def parse(gff_file, base=None):
+	logger = logging.getLogger(parse.__name__)
+
 	ins_file=gff_file.replace(".gff","")+".ins"
 	insertions=None if not os.path.exists(ins_file) else Fasta.parse(ins_file, todict=True)
+	if insertions is None:
+		logger.warn("Insertion sequence file %s missing" % ins_file)
+
 	calls=[]
 	for entry in open(gff_file, "r"):
 		if entry.startswith("#"): continue
@@ -137,7 +142,7 @@ def parse(gff_file, base=None):
 				del call.attributes["Iseq"]
 			calls.append(call)
 		except:
-			print >> sys.stderr, "Unable to parse line: %s" % entry
+			logger.error("Unable to parse line: %s" % entry)
 			raise
 	return calls
 
diff --git a/breakseq2/breakseq_index.py b/breakseq2/breakseq_index.py
index fd5a6ff..190ea6e 100755
--- a/breakseq2/breakseq_index.py
+++ b/breakseq2/breakseq_index.py
@@ -1,6 +1,7 @@
 import argparse
 import sys
 import os
+import logging
 from biopy.io import Fasta
 from biopy.io import SV
 
@@ -21,15 +22,28 @@ def get_seq(sv, jn_type, seq, format_version):
     return ">%s:%s:%s\n%s" % (sv.id, sv.size(), jn_type, seq)
 
 
-def generate_bplib(gff, reference, output, junction_length=DEFAULT_JUNCTION_LENGTH, format_version=DEFAULT_FORMAT_VERSION):
+def generate_bplib(gff, reference, output, junction_length=DEFAULT_JUNCTION_LENGTH, format_version=DEFAULT_FORMAT_VERSION, chromosomes=[]):
+    logger = logging.getLogger(generate_bplib.__name__)
+
     if not gff or not os.path.isfile(gff):
+        logger.error("GFF file unspecified of missing")
         raise Exception("GFF file unspecified or missing")
 
     outfd = open(output, "w") if output else sys.stdout
-    insertion_sequence_file = gff.replace(".gff", "") + ".ins";
-    if not os.path.isfile(insertion_sequence_file):
-        raise Exception("Insertion sequence file %s missing" % insertion_sequence_file)
+
+    ins_file = gff.replace(".gff", "") + ".ins"
+    ins_file_absent = not os.path.isfile(ins_file)
+    if ins_file_absent:
+        logger.error("Insertion sequence file %s not found. Insertions will be skipped" % ins_file)
+
     for sv in SV.parse(gff, Fasta.Seqs(reference, junction_length)):
+        if chromosomes and sv.name not in chromosomes:
+            continue
+ 
+        if sv.is_insertion() and ins_file_absent:
+            logger.warn("Omitting entry %s due to missing insertion sequence file" % sv.id)
+            continue
+
         flanks = sv.get_flanks()
         if sv.is_insertion():
             if flanks[0] is None or flanks[1] is None:
diff --git a/scripts/breakseq2_gen_bplib.py b/scripts/breakseq2_gen_bplib.py
index 3180174..90d0df6 100755
--- a/scripts/breakseq2_gen_bplib.py
+++ b/scripts/breakseq2_gen_bplib.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 
+import sys
 import argparse
+import logging
 from breakseq2 import breakseq_index, _version
 
 if __name__ == "__main__":
@@ -9,7 +11,20 @@
     breakseq_index.add_options(parser)
     parser.add_argument("--reference", help="Reference FASTA", required=True)
     parser.add_argument("--output", help="Output FASTA to generate. Leave unspecified for stdout")
+    parser.add_argument("--chromosomes", nargs="+", help="List of chromosomes to process", default=[])
     parser.add_argument('--version', action='version', version='%(prog)s ' + _version.__version__)
+    parser.add_argument('--log', help="Log level", default="INFO")
+
     args = parser.parse_args()
 
-    breakseq_index.generate_bplib(args.bplib_gff, args.reference, args.output, args.junction_length, args.format_version)
+    loglevel = getattr(logging, args.log.upper(), None)
+    if not isinstance(loglevel, int):
+        raise ValueError('Invalid log level: %s' % args.log)
+
+    FORMAT = '%(levelname)s %(asctime)-15s %(name)-20s %(message)s'
+    logging.basicConfig(level=loglevel, format=FORMAT)
+
+    logger = logging.getLogger(__file__)
+    logger.info("Command-line: " + " ".join(sys.argv))
+    
+    breakseq_index.generate_bplib(args.bplib_gff, args.reference, args.output, args.junction_length, args.format_version, args.chromosomes)