Remove uses of MATCHING environment variable and make patchpiracysums offer advice when it fails

Makefile

@@ -1,7 +1,6 @@
 # User configurable
 
 ROMID ?= ntsc-final
-MATCHING ?= 1
 PIRACYCHECKS ?= 1
 
 QEMU_IRIX ?= tools/irix/qemu-irix
@@ -152,7 +151,7 @@ $(B_DIR)/pd.z64: $(B_DIR)/stage3.bin $(ASSET_FILES)
 # the ROM to 32MB.
 $(B_DIR)/stage3.bin: $(B_DIR)/stage2.bin $(B_DIR)/segments/gamezips.bin
 	@cp $< $@.tmp
-	MATCHING=$(MATCHING) tools/packrom $@.tmp && mv $@.tmp $@
+	tools/packrom $@.tmp && mv $@.tmp $@
 
 # Stage2 takes stage1 and calculates the piracy checksums.
 $(B_DIR)/stage2.bin: $(B_DIR)/stage1.bin

tools/packrom

@@ -132,15 +132,13 @@ def main():
 
     fd = open(sys.argv[1], 'rb+')
 
-    if os.environ['MATCHING'] == '1':
-        write_garbage(fd, locations)
+    write_garbage(fd, locations)
 
     pack_lib(fd, locations)
     pack_data(fd, locations)
     pack_game(fd, locations)
 
-    if os.environ['MATCHING'] == '1':
-        fill_tail(fd)
+    fill_tail(fd)
 
     # Truncate to 32MB
     fd.seek(0)

tools/patchpiracysums

@@ -165,10 +165,14 @@ class Tool:
             pos += 4
 
         if upperpos is None or lowerpos is None:
-            print('0x%08x' % checksum)
-            raise ValueError('Unable to find checksum location in %s (upperpos=%s, lowerpos=%s)' % (
-                patchfunc, upperpos, lowerpos
-            ))
+            print('Unable to find placeholder checksum in %s.' % patchfunc)
+            print('This can happen if you\'ve turned PIRACYCHECKS off, built the files, then turned it on without rebuilding.')
+            print('To fix, try running the following:')
+            print('')
+            print('    touch $(grep -lr PIRACYCHECKS src)')
+            print('    make')
+            print('')
+            exit(1)
 
         self.fd.seek(upperpos)
         self.fd.write((0x3c010000 | (checksum >> 16)).to_bytes(4, 'big'))
@@ -200,7 +204,7 @@ class Tool:
 
         self.fd.close()
 
-if os.environ['PIRACYCHECKS']:
+if os.environ['PIRACYCHECKS'] == '1':
     tool = Tool()
     tool.run()