Program: 156529
Project: 156529
Buggy source:
@Override public boolean writeToWorld(IBuilderContext context){
  if (internalRequirementRemovalListener != null) {
    internalRequirementRemovalListener.remove(this);
  }
  if (mode == Mode.ClearIfInvalid) {
    if (!getSchematic().isAlreadyBuilt(context,x,y,z)) {
      if (BuildCraftBuilders.dropBrokenBlocks) {
        return BlockUtils.breakBlock((WorldServer)context.world(),x,y,z);
      }
 else {
        context.world().setBlockToAir(x,y,z);
        return true;
      }
    }
  }
 else {
    try {
      getSchematic().placeInWorld(context,x,y,z,stackConsumed);
      if (!getSchematic().isAlreadyBuilt(context,x,y,z)) {
        return false;
      }
      if (!context.world().isAirBlock(x,y,z) && getSchematic().getBuildingPermission() == BuildingPermission.ALL && getSchematic() instanceof SchematicBlock) {
        SchematicBlock sb=(SchematicBlock)getSchematic();
        ItemStack[] oldRequirementsArray=sb.storedRequirements;
        List<ItemStack> oldRequirements=Arrays.asList(oldRequirementsArray);
        sb.storedRequirements=new ItemStack[0];
        sb.storeRequirements(context,x,y,z);
        for (        ItemStack s : sb.storedRequirements) {
          boolean contains=false;
          for (          ItemStack ss : oldRequirements) {
            if (StackHelper.isEqualItem(s,ss)) {
              contains=true;
              break;
            }
          }
          if (!contains) {
            BCLog.logger.warn("String_Node_Str");
            BCLog.logger.warn("String_Node_Str" + x + "String_Node_Str"+ y+ "String_Node_Str"+ z+ "String_Node_Str"+ s.toString());
            context.world().removeTileEntity(x,y,z);
            context.world().setBlockToAir(x,y,z);
            return false;
          }
        }
        sb.storedRequirements=oldRequirementsArray;
      }
      TileEntity e=context.world().getTileEntity(x,y,z);
      if (e != null) {
        e.updateEntity();
      }
      return true;
    }
 catch (    Throwable t) {
      t.printStackTrace();
      context.world().setBlockToAir(x,y,z);
      return false;
    }
  }
  return false;
}

Fixed version (ground truth):
@Override public boolean writeToWorld(IBuilderContext context){
  if (internalRequirementRemovalListener != null) {
    internalRequirementRemovalListener.remove(this);
  }
  if (mode == Mode.ClearIfInvalid) {
    if (!getSchematic().isAlreadyBuilt(context,x,y,z)) {
      if (BuildCraftBuilders.dropBrokenBlocks) {
        return BlockUtils.breakBlock((WorldServer)context.world(),x,y,z);
      }
 else {
        context.world().setBlockToAir(x,y,z);
        return true;
      }
    }
  }
 else {
    try {
      getSchematic().placeInWorld(context,x,y,z,stackConsumed);
      if (!getSchematic().isAlreadyBuilt(context,x,y,z)) {
        return false;
      }
      if (!context.world().isAirBlock(x,y,z) && getSchematic().getBuildingPermission() == BuildingPermission.ALL && getSchematic() instanceof SchematicBlock) {
        SchematicBlock sb=(SchematicBlock)getSchematic();
        ItemStack[] oldRequirementsArray=sb.storedRequirements;
        List<ItemStack> oldRequirements=Arrays.asList(oldRequirementsArray);
        sb.storedRequirements=new ItemStack[0];
        sb.storeRequirements(context,x,y,z);
        for (        ItemStack s : sb.storedRequirements) {
          boolean contains=false;
          for (          ItemStack ss : oldRequirements) {
            if (getSchematic().isItemMatchingRequirement(s,ss)) {
              contains=true;
              break;
            }
          }
          if (!contains) {
            BCLog.logger.warn("String_Node_Str");
            BCLog.logger.warn("String_Node_Str" + x + "String_Node_Str"+ y+ "String_Node_Str"+ z+ "String_Node_Str"+ s.toString());
            context.world().removeTileEntity(x,y,z);
            context.world().setBlockToAir(x,y,z);
            return false;
          }
        }
        sb.storedRequirements=oldRequirementsArray;
      }
      TileEntity e=context.world().getTileEntity(x,y,z);
      if (e != null) {
        e.updateEntity();
      }
      return true;
    }
 catch (    Throwable t) {
      t.printStackTrace();
      context.world().setBlockToAir(x,y,z);
      return false;
    }
  }
  return false;
}