diff --git a/build/ab.mk b/build/ab.mk
index 177d0edd..2b0b6343 100644
--- a/build/ab.mk
+++ b/build/ab.mk
@@ -29,7 +29,7 @@ endif
 EXT ?=
 
 ifeq ($(PROGRESSINFO),)
-rulecount := $(shell test -f $(OBJ)/build.mk && $(MAKE) -n $(MAKECMDGOALS) PROGRESSINFO=XXXPROGRESSINFOXXX | grep XXXPROGRESSINFOXXX | wc -l)
+rulecount := $(shell $(MAKE) -q $(OBJ)/build.mk PROGRESSINFO=1 && $(MAKE) -n $(MAKECMDGOALS) PROGRESSINFO=XXXPROGRESSINFOXXX | grep XXXPROGRESSINFOXXX | wc -l)
 ruleindex := 1
 PROGRESSINFO = "$(shell $(PYTHON) build/_progress.py $(ruleindex) $(rulecount))$(eval ruleindex := $(shell expr $(ruleindex) + 1))"
 endif
@@ -53,8 +53,8 @@ clean::
 
 export PYTHONHASHSEED = 1
 build-files = $(shell find . -name 'build.py') $(wildcard build/*.py) $(wildcard config.py)
-$(OBJ)/build.mk: Makefile $(build-files)
+$(OBJ)/build.mk: Makefile $(build-files) build/ab.mk
 	@echo "AB"
 	@mkdir -p $(OBJ)
-	$(hide) $(PYTHON) -X pycache_prefix=$(OBJ) build/ab.py -o $@ build.py \
+	$(hide) $(PYTHON) -X pycache_prefix=$(OBJ)/__pycache__ build/ab.py -o $@ build.py \
 		|| rm -f $@
diff --git a/build/ab.py b/build/ab.py
index d10e7da9..9eeea485 100644
--- a/build/ab.py
+++ b/build/ab.py
@@ -154,6 +154,9 @@ def __init__(self, cwd, name):
     def __eq__(self, other):
         return self.name is other.name
 
+    def __lt__(self, other):
+        return self.name < other.name
+
     def __hash__(self):
         return id(self)
 
@@ -314,7 +317,12 @@ def targetof(value, cwd=None):
             # Load the new build file.
 
             path = join(path, "build.py")
-            loadbuildfile(path)
+            try:
+                loadbuildfile(path)
+            except ModuleNotFoundError:
+                error(
+                    f"no such build file '{path}' while trying to resolve '{value}'"
+                )
             assert (
                 value in targets
             ), f"build file at '{path}' doesn't contain '+{target}' when trying to resolve '{value}'"
@@ -411,7 +419,7 @@ def emit_rule(name, ins, outs, cmds=[], label=None):
     emit(".PHONY:", name, into=lines)
     if outs:
         emit(name, ":", *fouts, into=lines)
-        emit(*fouts, "&:", *fins, "\x01", into=lines)
+        emit(*fouts, "&:" if len(fouts) > 1 else ":", *fins, "\x01", into=lines)
 
         if label:
             emit("\t$(hide)", "$(ECHO) $(PROGRESSINFO) ", label, into=lines)
diff --git a/build/utils.py b/build/utils.py
index ac57304e..17040a8f 100644
--- a/build/utils.py
+++ b/build/utils.py
@@ -8,8 +8,8 @@
     error,
     simplerule,
 )
-from os.path import relpath, splitext, join, basename
-from glob import glob
+from os.path import relpath, splitext, join, basename, isfile
+from glob import iglob
 import fnmatch
 import itertools
 
@@ -30,7 +30,7 @@ def collectattrs(*, targets, name, initial=[]):
     s = set(initial)
     for a in [t.args.get(name, []) for t in targets]:
         s.update(a)
-    return list(s)
+    return sorted(list(s))
 
 
 def itemsof(pattern, root=None, cwd=None):
@@ -43,9 +43,10 @@ def itemsof(pattern, root=None, cwd=None):
     root = join(cwd, root)
 
     result = {}
-    for f in glob(pattern, recursive=True):
+    for f in iglob(pattern, recursive=True):
         try:
-            result[relpath(f, root)] = f
+            if isfile(f):
+                result[relpath(f, root)] = f
         except ValueError:
             error(f"file '{f}' is not in root '{root}'")
     return result