tikzcd and tikzexternalize

[bartsnapp]

https://tex.stackexchange.com/questions/171931/are-the-tikz-libraries-cd-and-external-incompatible-with-one-another

[kisonecat]

The following works:

\usepackage{tikz-cd}

\begin{tikzpicture}
\node {\begin{tikzcd}[row sep=huge,baseline = (B.base)]
  A \arrow[rd] \arrow[r, "\varphi"] & |[alias=B]| B \\ & C
\end{tikzcd}};
\end{tikzpicture}