这不是一个可重复例子…

问题

最近的一个项目里我想在学校机群里编译Rmd生成结果报告，碰到的问题是没有可视化模块的话Rmd编译失败。
而且还有无root权限的限制。
参考了这个issue
跟SO
之后，多种办法试过还是无法编译。用以下代码编译还出错
R -e "rmarkdown::render('script.Rmd',output_file='output.html')"

装xvfb没root的话看起来好麻烦，还没试过

尝试

直接运行

---
title: "Untitled"
author: "TC"
date: "12/20/2019"
output: 
    html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
#options(bitmapType='cairo')
```


## R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

```{r cars}
summary(cars)
```

## Including Plots

You can also embed plots, for example:


Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.

编译后出错：

> rmarkdown::render('test.Rmd',output_file='output.html')


processing file: test.Rmd
  |..............                                                        |  20%
  ordinary text without R code

  |............................                                          |  40%
label: setup (with options) 
List of 1
 $ include: logi FALSE

Quitting from lines 10-12 (test.Rmd) 
Error in dev.control(displaylist = if (record) "enable" else "inhibit") : 
  dev.control() called without an open graphics device
Calls: <Anonymous> ... call_block -> block_exec -> chunk_device -> dev.control
In addition: Warning messages:
1: In grDevices::png(f) : no png support in this version of R
2: In (function (filename = if (onefile) "Rplots.svg" else "Rplot%03d.svg",  :
  unable to load shared object '/sw/R/3.5.2/lib64/R/library/grDevices/libs//cairo.so':
  /sw/R/3.5.2/lib64/R/library/grDevices/libs//cairo.so: cannot open shared object file: No such file or directory
3: In (function (filename = if (onefile) "Rplots.svg" else "Rplot%03d.svg",  :
  failed to load cairo DLL

Execution halted

Capabilities显示各种png 啊jpg啊cairo啊都不支持

> capabilities()
       jpeg         png        tiff       tcltk         X11        aqua 
      FALSE       FALSE       FALSE       FALSE       FALSE       FALSE 
   http/ftp     sockets      libxml        fifo      cledit       iconv 
       TRUE        TRUE        TRUE        TRUE        TRUE        TRUE 
        NLS     profmem       cairo         ICU long.double     libcurl 
       TRUE        TRUE       FALSE        TRUE        TRUE        TRUE

Cairo包

目前尝试到装了Cairo后可以出图

> Cairo.capabilities()
   png   jpeg   tiff    pdf    svg     ps    x11    win raster 
  TRUE   TRUE   TRUE   TRUE   TRUE   TRUE   TRUE  FALSE   TRUE

感觉很近了，不过试图设置dev依然失败，代码

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE, dev="Cairo::CairoPNG")
```

报错：

Quitting from lines 10-11 (test2.Rmd) 
Error in dev.control(displaylist = if (record) "enable" else "inhibit") : 
  dev.control() called without an open graphics device
Calls: <Anonymous> ... call_block -> block_exec -> chunk_device -> dev.control

所以说

求解救怎么才能在这种服务器上优雅的编译Rmd啊…

我现在的替代方案可是手写bash+一堆echo语句来生成html啊…