Important information As of September 7, 2015, the
tikz-bayesnet package in TeX Live has been upddated, so the following answer is not relevant for whoever has revision 38295 in TeX Live.
tlmgr tikz-bayesnet gives
shortdesc: Draw Bayesian networks, [...]
or a larger revision number, the problem should not appear.
I suggest you to install MacTeX from the image you get at http://tug.org/mactex, rather than with Homebrew (which is what they recommend, too).
Your screen shot suggests you're using TeX Live Utility and indeed the response is good. Unfortunately, the packaging of
tikz-bayesnet is wrong. If I do
tlmgr info tikz-bayesnet --list
from the terminal, the output is
shortdesc: Draw Bayesian networks, graphical models and directed factor graphs.
longdesc: The package provides a library supporting the display of Bayesian networks, graphical models and (directed) factor graphs in LaTeX.
sizes: doc: 85k
cat-date: 2014-02-26 23:03:13 +0100
Included files, by type:
One can check this also with TeX Live Utility, by right clicking on the package name in the main window (“Packages” tab), to get
Alas! The file
tikzlibrarybayesnet.code.tex ends up in the
doc subtree, instead of the
tex one. The correct response should be
It's a bug that should be made known in the TeX Live mailing list
Meanwhile, you can do
mkdir -p ~/Library/texmf/tex/latex/tikz-bayesnet
cp /usr/local/texlive/2015/texmf-dist/doc/latex/tikz-bayesnet/tikzlibrarybayesnet.code.tex ~/Library/texmf/tex/latex/tikz-bayesnet
remembering to remove the file when the bug is solved.
Instead of using the terminal you can also copy the file manually in the Finder, creating the folders under
~/Library/texmf as shown.