--- a/ProjectBuilder.st	Fri Oct 23 15:38:38 2009 +0200
+++ b/ProjectBuilder.st	Fri Oct 23 16:11:15 2009 +0200
@@ -369,14 +369,18 @@
     ].
 
     files do:[:dllRelativePath |
-        ((buildDirectory / 'stx' / dllRelativePath) exists
-        and:[ (mySTXTopDirectory / dllRelativePath) fileSize = (buildDirectory / 'stx' / dllRelativePath) fileSize
-        and:[ (mySTXTopDirectory / dllRelativePath) modificationTime < (buildDirectory / 'stx' / dllRelativePath) modificationTime
-        "/ and:[ (mySTXTopDirectory / dllRelativePath) sameContentsAs:(targetBuildDir / dllRelativePath) ]
-        ]]) ifFalse:[
-            (buildDirectory / 'stx' / dllRelativePath) directory recursiveMakeDirectory.
-            (mySTXTopDirectory / dllRelativePath) copyTo:(buildDirectory / 'stx' / dllRelativePath).    
-        ]
+        (mySTXTopDirectory / dllRelativePath) exists ifTrue:[
+            ((buildDirectory / 'stx' / dllRelativePath) exists
+            and:[ (mySTXTopDirectory / dllRelativePath) fileSize = (buildDirectory / 'stx' / dllRelativePath) fileSize
+            and:[ (mySTXTopDirectory / dllRelativePath) modificationTime < (buildDirectory / 'stx' / dllRelativePath) modificationTime
+            "/ and:[ (mySTXTopDirectory / dllRelativePath) sameContentsAs:(targetBuildDir / dllRelativePath) ]
+            ]]) ifFalse:[
+                (buildDirectory / 'stx' / dllRelativePath) directory recursiveMakeDirectory.
+                (mySTXTopDirectory / dllRelativePath) copyTo:(buildDirectory / 'stx' / dllRelativePath).    
+            ]
+        ] ifFalse:[
+            self error:'Missing file: ',dllRelativePath printString mayProceed:true.
+        ].
     ].
 !