knitr 又不听话了，自动生成 _files/ 这能忍？

这几天在整理 thesis 的几个 repo，把生成图片的代码做成可以 run 的 .Rmd 自然不必说。

昨天还好好的，今天突然冒出来一个 ***_files/，打开看一下，基本都是垃圾，

├── [   0]  fonts
│   ├── [ 20K]  open-sans-400.woff
│   └── [ 21K]  open-sans-700.woff
├── [   0]  images
│   ├── [3.1K]  body-bg.jpg
│   ├── [8.7K]  body-bg.png
│   ├── [ 10K]  header-bg.jpg
│   └── [ 33K]  highlight-bg.jpg
└── [3.7K]  style.css

I guess there are some problems with prettydoc::html_pretty, so I change to html_document: default, but it also produces the folder (although empty).

Then I try CRAN version of knitr & rmakrdown, which doesn’t help.

Later, I try to add rm -r ***_files/ in tasks.json. Work as it does, I don’t feel it’s the appropriate way.

To beat a dead horese, I ramble on other repos ¹. Suddenly I find lulab-rotation-summary doesen’t have the problem. Looking at the .Rmd code for a while, the reason seems to be customing fig.path.

Finally I find a solution:

knitr::opts_chunk$set(fig.path = '/tmp/') # prevent trash `_files/`, not know why

I admit it’s not perfact, but I can’t think up a better one at the moment.