diff --git a/make/projects-dir.mk b/make/projects-dir.mk
index 9b82aaf8..49fe6e43 100644
--- a/make/projects-dir.mk
+++ b/make/projects-dir.mk
@@ -45,7 +45,8 @@ ifeq ($(CVS_RSH),)
   export CVS_RSH
 endif
 
-PGIT   = CLONE_PROJECTS="$(PROJECTS)" PGIT_CLONE_FROM_USER="$(JANWARE_USER)" /bin/bash $(firstword $(wildcard ./ytools/devutil/scripts/pgit.sh /opt/ytools/bin/pgit.sh))
+PGIT     = CLONE_PROJECTS="$(PROJECTS)" PGIT_CLONE_FROM_USER="$(JANWARE_USER)" /bin/bash $(firstword $(wildcard ./ytools/devutil/scripts/pgit.sh /opt/ytools/bin/pgit.sh))
+BUILD_PY = python ./ytools/devutil/scripts/build.py -b $(shell pwd) $(BUILD_PY_EXTRA_OPTS)
 
 EXCLUDE_FROM_BUILD = \
 	dspider-btools \
@@ -59,15 +60,15 @@ EXCLUDE_FROM_BUILD = \
 all: links.done clone.done cvs-update.done
 
 all clean: config.done
-	python ./ytools/devutil/scripts/build.py -b $(shell pwd) $@ $(filter-out $(EXCLUDE_FROM_BUILD),$(PROJECTS))
+	$(BUILD_PY) $@ $(filter-out $(EXCLUDE_FROM_BUILD),$(PROJECTS))
 
 pkg-%:
-	python ./ytools/devutil/scripts/build.py -b $(shell pwd) $@ $(filter-out $(EXCLUDE_FROM_BUILD),$(PROJECTS))
+	$(BUILD_PY) $@ $(filter-out $(EXCLUDE_FROM_BUILD),$(PROJECTS))
 
 clean: done.clean
 
 clean-dirs:
-	ls */dirs-all.done 2>/dev/null | sed 's%/.*%%' | xargs -r build.py -b $(shell pwd) clean
+	ls */dirs-all.done 2>/dev/null | sed 's%/.*%%' | xargs -r $(BUILD_PY) clean
 
 cpp:
 	@find $(PROJECTS) -name '*.cpp' | grep /worker/ | grep -ve "old\|tmp\|nomake\|new" | \
diff --git a/scripts/build.py b/scripts/build.py
index 9574122c..fd4ec283 100644
--- a/scripts/build.py
+++ b/scripts/build.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python -u
 # -*- coding: iso-8859-15 -*-
 
+from __future__ import print_function
 import os
 import sys
 import dircache
@@ -22,6 +23,10 @@ search_path=[".", "dspc/src", "dspc/src/dspcd-plugins", "dspc/src/io" ]
 glob_prereq_type="BUILD"
 dep_cache = {}
 
+def debug(*objs):
+    if args.debug:
+        print("DEBUG: ", *objs, file=sys.stderr)
+
 def find_proj_path(name):
     name=name.replace("dspider-", "")
     for sub in search_path:
@@ -50,7 +55,7 @@ def read_deps(cur, prereq_type):
         r.add(d)
     if cur in r:
         r.remove(cur)
-    #print 'inserting', prereq_type, cur, r
+    debug('inserting', prereq_type, "prerequisites of", cur, ":", ' '.join(r))
     dep_cache[prereq_type][cur] = r
     return r
 
@@ -72,7 +77,7 @@ def calculate_order(order, modules, prereq_type):
             if not len(dep_tree[d]):
                 break
         else:
-            print all_deps
+            print(all_deps)
             raise Exception("fatal: the dependencies between these modules are unresolvable")
         order.append(d)
         all_deps.remove(d)
@@ -83,7 +88,7 @@ def calculate_order(order, modules, prereq_type):
 
 def run_make(module, target):
     path = find_proj_path(module)
-    print "========= running make " + target + " in " + path
+    print("========= running make " + target + " in " + path)
     os.chdir(path)
     if subprocess.call(["make", target]):
         raise Exception(time.strftime("%Y-%m-%d %H:%M") + ": failed to make target " + target + " in module " + module + " below base " + proj_base)
@@ -95,7 +100,7 @@ def build(modules, order, target):
             if m in modules:
                 modules.remove(m)
             if not len(modules):
-                print "all modules cleaned"
+                print("all modules cleaned")
                 return
     else:
         for m in order:
@@ -107,10 +112,15 @@ modules = Set()
 parser = argparse.ArgumentParser(description='jannet software project build tool')
 parser.add_argument('--base', '-b', nargs='?', default=proj_base, help='Project base directory')
 parser.add_argument('--exclude', nargs='?', default='', help='List of modules to be excluded from build')
+parser.add_argument('--debug', '-d', action='store_true',
+    default=False, help='Output debug information to stderr')
 parser.add_argument('target', default='all', help='Build target')
 parser.add_argument('modules', nargs='+', default='', help='Modules to be built')
 
 args=parser.parse_args()
+
+debug("----------------------------------------- running ", ' '.join(sys.argv))
+
 proj_base=args.base
 exclude=args.exclude
 target=args.target
@@ -118,21 +128,21 @@ modules=args.modules
 
 env_exclude=os.getenv('BUILD_EXCLUDE', '')
 if len(env_exclude):
-    print "exluding modules from environment: " + env_exclude
+    print("exluding modules from environment: " + env_exclude)
     exclude += " " + env_exclude
 
 # -- build
 if target != 'order':
-    print "calculating order for modules: " + ' '.join(modules)
+    print("calculating order for modules: " + ' '.join(modules))
 order = []
 calculate_order(order, modules, glob_prereq_type)
 order = [m for m in order if m not in exclude]
 if target == 'order':
-    print ' '.join(order)
+    print(' '.join(order))
     exit(0)
 
-print "order is: " + ' '.join(order)
+print("order is: " + ' '.join(order))
 build(modules, order, target)
 
-print datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+print(datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))