This question, and most of the other answers here, arise from a misunderstanding of how projects using the GNU Build System (a.k.a. Autotools) are distributed. In fact, in the case of the Erlang XMPP library mentioned by the OP, the misunderstanding appears to be on the part of the developers.
Obtaining the software the right way
If all you want to do is compile and install a project released with the GNU Autotools, then you should not check it out from the source control system. You should instead download the packaged source release provided by the developer. These normally take the form of tarballs distributed on the project's website. For projects that are hosted entirely on GitHub, Savannah, or some similar hosting service, these tarballs will usually be found behind some link labelled "Download" or "Releases". You untar the package and utter some variant of the standard ./configure && make && sudo make install incantation. That's all; you don't need to invoke any of the GNU Autotools, and don't even need to have the GNU Autotools installed on your system.
The reason that you, the user, don't need the GNU Autotools to compile an Autotools-packaged project is that the developer has already used the various Autotools programs to generate a "distribution tarball" that can be used to build the software on any Unix-like system. The distribution tarball contains a highly portable configure script that scans the build environment, checks for dependencies, and constructs a Makefile customized to your system.
So when do you need Autotools?
The only reason you should need to install and invoke the GNU Autotools yourself is if you want to do development work on a project built with Autotools. And even then, you probably won't need the Autotools unless you change the project's dependencies. In that case, you would indeed need to check out the original source, make appropriate changes to the Autotools-specific input files (configure.ac, Makefile.am, etc.), and run the Autotools on them to generate a new configure file. If you want to independently publish the revised package, then you would use the Makefile generated by Autotools to generate a new distribution tarball, and then publish that tarball somewhere online.
The problem is that some developers make their source repository publically available but neglect to publish their distribution tarballs (or make it difficult to find where they are published). For example, rather than publishing their distribution tarballs as GitHub Releases, the Erlang XMPP library's GitHub Releases are tarballs of the raw source repository. This makes it impossible to compile the project without the GNU Autotools, defeating the entire purpose of using Autotools in the first place.
TL;DR summary
The GNU Autotools are something that developers use to make portable source code packages for users. Users should download and compile from these source packages, not the original code from the source control system. If the developers don't provide these source packages, then they aren't using Autotools correctly, and should be gently slapped with a wet trout until they see the error of their ways.
