[5]第 3 章[6] (/usr/share/texlive/texmf-dist/tex/latex/psnfss/omspcr.fd)! Improper discretionary list.\textbackslash ...tionary {\sphinx@textbackslash }                                                  {\sphinxafterbreak }{\sphi...l.196 ...nxcode{\sphinxupquote{\textbackslash{}0}}                                                   が埋め込まれていても大丈...? ! Emergency stop.\textbackslash ...tionary {\sphinx@textbackslash }                                                  {\sphinxafterbreak }{\sphi...l.196 ...nxcode{\sphinxupquote{\textbackslash{}0}}                                                   が埋め込まれていても大丈...Output written on howto-sockets.dvi (6 pages, 23844 bytes).Transcript written on howto-sockets.log.Latexmk: Index file 'howto-sockets.idx' was writtenLatexmk: References changed.Collected error summary (may duplicate other messages):  latex: Command for 'latex' gave return code 256Latexmk: Use the -f option to force complete processing, unless error was exceeding maximum runs of latex/pdflatex.Latexmk: Errors, so I did not complete making targetsMakefile:35: recipe for target 'howto-sockets.pdf' failed