MacOS Install error for valhalla/valhalla/prime_server

[brad-4k]

Command: % brew install valhalla/valhalla/prime_server

Result:
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> Updated Formulae
Updated 2 formulae.

==> Tapping valhalla/valhalla
Cloning into '/usr/local/Homebrew/Library/Taps/valhalla/homebrew-valhalla'...
remote: Enumerating objects: 84, done.
remote: Counting objects: 100% (4/4), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 84 (delta 0), reused 0 (delta 0), pack-reused 80
Unpacking objects: 100% (84/84), done.
Tapped 2 formulae (97 files, 42.4KB).
==> Cloning https://github.com/kevinkreiser/prime_server.git
Cloning into '/Users/bradcolbert/Library/Caches/Homebrew/prime_server--git'...
==> Checking out tag 0.7.0
HEAD is now at bfd1534 prepare for release
Submodule 'logging' (https://gist.github.com/39f2e39273c625d96790.git) registered for path 'src/logging'
Submodule 'testing' (https://gist.github.com/ada902fb51a1ad1e5a27.git) registered for path 'test/testing'
Cloning into '/Users/bradcolbert/Library/Caches/Homebrew/prime_server--git/src/logging'...
Cloning into '/Users/bradcolbert/Library/Caches/Homebrew/prime_server--git/test/testing'...
Submodule path 'src/logging': checked out '10ba199d1e23b356c3446b723289a602663d41ec'
Submodule path 'test/testing': checked out '1c45352fa2c4e25a748cf1221b93a9aed4dbc34c'
/Users/bradcolbert/Library/Caches/Homebrew/prime_server--git/src/logging
/Users/bradcolbert/Library/Caches/Homebrew/prime_server--git/test/testing
==> Installing prime_server from valhalla/valhalla
==> ./autogen.sh
Last 15 lines from /Users/bradcolbert/Library/Logs/Homebrew/prime_server/01.autogen.sh:
configure.ac:28: warning: The macro `AC_LANG_CPLUSPLUS' is obsolete.
configure.ac:28: You should run autoupdate.
./lib/autoconf/c.m4:262: AC_LANG_CPLUSPLUS is expanded from...
configure.ac:28: the top level
configure.ac:37: warning: $as_echo is obsolete; use AS_ECHO(["message"]) instead
lib/m4sugar/m4sh.m4:692: _AS_IF_ELSE is expanded from...
lib/m4sugar/m4sh.m4:699: AS_IF is expanded from...
./lib/autoconf/general.m4:2249: AC_CACHE_VAL is expanded from...
./lib/autoconf/general.m4:2270: AC_CACHE_CHECK is expanded from...
m4/ax_pthread.m4:88: AX_PTHREAD is expanded from...
configure.ac:37: the top level
configure.ac:2: error: possibly undefined macro: m4_esyscmd
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
autoreconf: error: /usr/local/Cellar/autoconf/2.71/bin/autoconf failed with exit status: 1