I want to embed dot scripts within .lyx files, I added the following line:
(In document LaTeX preamble: )
\usepackage{graphviz}
however, latex errored:
LaTeX Error: File `graphviz.sty' not found.
lyx should know .dot files itself when graphviz is correctly installed. no need for preamble hacking, just insert it as a normal picture.
Well, it seems you don't have the graphviz.sty package correctly installed. Maybe this can help you. Anyway there are other ways to embed Graphviz in LaTeX, see a previuos answer of mine.