Quadruple backslashes

[kwstat]

System: Windows 7 using MiKTeX.

When I load some packages, the startup messages about function name conflicts are causing problems when processing the tex files into pdf.

For example, here is part a knitr-generated tex file:

---

{\ttfamily\noindent\itshape\textcolor{messagecolor}{Loading required package: MCMCglmm}}

{\ttfamily\noindent\itshape\textcolor{messagecolor}{Loading required package: tensorA}}

{\ttfamily\noindent\itshape\textcolor{messagecolor}{\\Attaching package: 'tensorA'}}

{\ttfamily\noindent\itshape\textcolor{messagecolor}{The following object(s) are masked from 'package:Matrix':\\\\    norm}}

---

Note the last line with the quadruple backslashes.

Then when I try to convert this to pdf, I get this error:

---

! LaTeX Error: There's no line here to end.
See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.252 ...asked from 'package:Matrix':\\\\    norm}
                                                  }
? 
! Emergency stop.
 ...

---

For now, I can eliminate the problem using suppressStartupMessages(), but a more elegant fix would be nice.

[yihui]

I remember this error message when I started learning LaTeX a few years ago, and I'm surprised now that it seems to have gone. With both TeXLive 2012 under Ubuntu and MikTeX 2.9 under Windows, I can no longer reproduce this error. The quadruple backslashes just compile fine...

So which version of MikTeX are you using?

[kwstat]

$ pdflatex --version
MiKTeX-pdfTeX 2.9.4535 (1.40.13) (MiKTeX 2.9 64-bit)
Copyright (C) 1982 D. E. Knuth, (C) 1996-2012 Han The Thanh
TeX is a trademark of the American Mathematical Society.

I'm using pdflatex for compiling. The relevant line from the tex file is this:

{\ttfamily\noindent\itshape\textcolor{messagecolor}{The following object(s) are masked from 'package:kw':\\\\    desplot, RedGrayBlue}}\begin{alltt}

When I use pdflatex to compile, I get this error:

$ pdflatex quadratic.tex


! LaTeX Error: There's no line here to end.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.236 ...package:kw':\\\\    desplot, RedGrayBlue}
                                                  }\begin{alltt}

[yihui]

Although I still cannot reproduce the error with the same version of pdflatex under Windows, I'll fix this problem by not using \\\\ any more.

[yihui]

Should be fixed now.

[github-actions]

This old thread has been automatically locked. If you think you have found something related to this, please open a new issue by following the issue guide (https://yihui.org/issue/), and link to this old issue if necessary.