--- a/src/configure.ac
+++ b/src/configure.ac
@@ -163,9 +163,10 @@
fi
fi
-# Enable use of file extended attributes.
-# Not by default as extended attributes are little used for now, and
-# looking for them is not completely trivial
+# Enable use of file extended attributes. Not by default as extended
+# attributes are little used for now, and looking for them is not
+# completely trivial: we have to use ctime instead of mtime to detect
+# changes.
AC_ARG_ENABLE(xattr,
AC_HELP_STRING([--enable-xattr],
[Enable fetching metadata from file extended attributes. This is only