I am trying to update an R markdown document that uses the {.tabset} option, but I'm not getting tabs, as expected. This same file generated fine the last time the report was generated (about six weeks ago). Both rmarkdown and pandoc have been updated since then, although I do not remember the exact versions that were used previously. Running under macOS Sierra 10.12.6, using R version 3.4.2, rmarkdown 1.8.2 and pandoc 2.0.2, the following does not create tabs:
---
title: "Missing Tabs"
output: html_document
---
# Tabset here {.tabset}
## tab1
```{r}
summary(cars)
```
## tab 2
```{r}
summary(pressure)
```
Other options (e.g., table of contents, appearance, styling) seem to be functioning correctly, but I can't figure out what's changed. Thanks!