There are several warnings of the type: ``` configure.ac:2: warning: The macro `AC_CANONICAL_SYSTEM' is obsolete. configure.ac:2: You should run autoupdate. ``` as just one example. Documentation on how to fix these can be found [here](https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.71/html_node/Obsolete-Constructs.html).