- * No incompatible changes within Exim itself, but the integrated support for
- dynamically loadable lookup modules has an ABI change from the modules
- supported by some OS vendors through an unofficial patch. Don't try to
- mix & match.
+ * The integrated support for dynamically loadable lookup modules has an ABI
+ change from the modules supported by some OS vendors through an unofficial
+ patch. Don't try to mix & match.
+
+ * Some parts of the build system are now beginning to assume that the host
+ environment is POSIX. If you're building on a system where POSIX tools are
+ not the default, you might have an easier time if you switch to the POSIX
+ tools. Feel free to report non-POSIX issues as a request for a feature
+ enhancement, but if the POSIX variants are available then the fix will
+ probably just involve some coercion. See the README instructions for
+ building on such hosts.