Commit https://github.com/quarto-dev/quarto-cli/commit/b055f78d7d6bf78f88428534b6637a8bfcd5d59c introduced a regression for me (first time using  `git bisect`, this is pretty cool!). I am serving a website project with `quarto preview` and when I change a file I get the following output / error:

```
ERROR: Error: Directory not empty (os error 39)
    at deno:core/01_core.js:106:46
    at unwrapOpResult (deno:core/01_core.js:126:13)
    at Object.opSync (deno:core/01_core.js:140:12)
    at Object.removeSync (deno:runtime/js/30_fs.js:148:10)
    at removeIfExists (file:///hits/fast/mbm/share/mbm-wiki/_dev/quarto-cli/src/core/path.ts:23:10)
    at file:///hits/fast/mbm/share/mbm-wiki/_dev/quarto-cli/src/command/render/freeze.ts:201:23
    at Array.map (<anonymous>)
    at pruneProjectFreezerDir (file:///hits/fast/mbm/share/mbm-wiki/_dev/quarto-cli/src/command/render/freeze.ts:201:9)
    at freezeLibDir (file:///hits/fast/mbm/share/mbm-wiki/_dev/quarto-cli/src/command/render/project.ts:253:13)
    at renderProject (file:///hits/fast/mbm/share/mbm-wiki/_dev/quarto-cli/src/command/render/project.ts:258:11)
```
Since I have the quarto repo in the project as well we get the full stack trace for the typescript code.

I noticed that after the error occurs there is a rogue `site_libs` folder in the root directory of the project that I assume should have been copied into the `_site` folder and then be delete but this step failed due to some file permissions? When I then cancel with `ctrl+c` and run the `preview` command again the changes propagate and the folder disappears.
2021-11-17T11:59:03Z
jmbuhr
closed
[regression] file permission error with `quarto preview`
https://github.com/quarto-dev/quarto-cli/issues/188