try

setup.py

@@ -52,14 +52,14 @@ def quote_argument(arg: str) -> str:
 
 class AmalgationLibSQLCipherBuilder(build_ext):
     def build_extension(self, ext):  # noqa  # type: ignore
-        sqlcipher_root = Path("sqlcipher")
-        sqlcipher_header = sqlcipher_root /  "sqlite3.h"
-        sqlcipher_source = sqlcipher_root / "sqlite3.c"
-        if not sqlcipher_header.exists() or not sqlcipher_source.exists():
+        sqlcipher_root = "sqlcipher"
+        sqlcipher_header = os.path.join(sqlcipher_root, "sqlite3.h")
+        sqlcipher_source = os.path.join(sqlcipher_root, "sqlite3.c")
+        if not os.path.exists(sqlcipher_header) or not os.path.exists(sqlcipher_source):
             raise RuntimeError("SQLCipher amalgamation not found")
 
-        ext.include_dirs.append(str(sqlcipher_root))
-        ext.sources.append(str(sqlcipher_source))
+        ext.include_dirs.append(sqlcipher_root)
+        ext.sources.append(sqlcipher_source)
 
         # build with fulltext search enabled
         ext.define_macros.append(("SQLITE_ENABLE_FTS3", "1"))