diff -r 98a76dbb1b6d -r ca814b175391 targets/toolchain_gcc.py
--- a/targets/toolchain_gcc.py	Fri Oct 28 14:26:17 2022 +0800
+++ b/targets/toolchain_gcc.py	Fri Oct 28 14:53:23 2022 +0800
@@ -136,7 +136,7 @@
         # read source
         src = open(os.path.join(self.buildpath, bn)).read()
         # compute new hash
-        newhash = hashlib.md5(src).hexdigest()
+        newhash = hashlib.md5(src.encode()).hexdigest()
         # compare
         match = (oldhash == newhash)
         if not match: