macports texlive can't find .sty file

Question

I have texlive-fonts-extra installed:

$ port installed texlive-fonts-extra
The following ports are currently installed:
  texlive-fonts-extra @22691_0+doc (active)

According to https://trac.macports.org/wiki/TeXLivePackages, texlive-fonts-extra has doublestroke

However, while compiling ($ pdflatex article.tex) a .tex file containing

\usepackage{mathtools, doublestroke}

I get

! LaTeX Error: File `doublestroke.sty' not found.

I am using the correct copy of latex since

$ which pdflatex
/opt/local/bin/pdflatex

What should I do to troubleshoot?

Answer 1

I don't think there is a doublestroke package. According to the documentation for doublestroke you need

\usepackage{dsfont}

Alternatively, you can access the font as follows, but the package is the better option.

\documentclass{article}
\font\dsrom=dsrom10 
\begin{document}
\[\hbox{\dsrom N}=\{0,1,2,\ldots\}\]
\[\hbox{\dsrom ABCDEFGHIJKLMNOPQRSTUVWXYZ}\]
\end{document}