[R-pkg-devel] Vignette fonts problem

[Göran Broström]

I have built and checked eha_2.8.2 with R-4.0.3 and everything is OK.

However, checking with the current (2020-12-12) R-devel, I get:

--- re-building ‘tpchreg.Rmd’ using rmarkdown
Quitting from lines 103-108 (tpchreg.Rmd)
Error: processing vignette 'tpchreg.Rmd' failed with diagnostics:
X11 font -adobe-helvetica-%s-%s-*-*-%d-*-*-*-*-*-*-*, face 1 at size 12 
could not be loaded
--- failed re-building ‘tpchreg.Rmd’

In 'tpchreg.Rmd' I have:

---
title: "Proportional hazards regression with tabular data"
author: "Göran Broström"
package: eha
date: "`r Sys.Date()`"
slug: eha
link-citations: yes
output:
     bookdown::html_document2:
         toc: yes
         toc_depth: 2
pkgdown:
     as_is: true
bibliography: mybib.bib
vignette: >
   %\VignetteIndexEntry{Proportional hazards regression with tabular data}
   %\VignetteEngine{knitr::rmarkdown}
   %\VignetteEncoding{UTF-8}
   \usepackage[utf8]{inputenc}
---

and the lines 103-108 are:

```{r glmbasefig,  fig.cap = "Age-specific mortality, Sweden 1968-2019. 
Poisson regression."}
oldpar <- par(las = 1, lwd = 1.5, mfrow = c(1, 2))
plot(0:(n-1), haz, type = "s", main = "log(hazards)",
      xlab = "Age", ylab = "", log = "y")
plot(0:(n-1), haz, type = "s", main = "hazards",
      xlab = "Age", ylab = "Deaths / Year")
```

So, why do I get the fonts error now (and not earlier) and where can I 
find the fonts? (Ubuntu 20.04). And will it help, so the package is 
accepted by CRAN?

Thanks, Göran