Formatting does not work with read only file system

[chrisrundlerfu]

Issue Type: Bug

When I try and format my python file I get the following error:

Failed to create a temporary file, Unable to write file '/Untitled-1.13264068d108c6901b3592ea654fcd57.tmp' (Unknown (FileSystemError): Error: EROFS: read-only file system, open '/Untitled-1.13264068d108c6901b3592ea654fcd57.tmp')

I am running a mac and format document works for other file types (e.g. json)

Extension version: 2020.8.106424
VS Code version: Code 1.48.2 (a0479759d6e9ea56afa657e454193f72aef85bd0, 2020-08-25T10:09:08.021Z)
OS version: Darwin x64 19.6.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2600)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	3, 3, 4
Memory (System)	32.00GB (0.42GB free)
Process Argv
Screen Reader	no
VM	0%

[karthiknadig]

@chrisrundlerfu Can you check if the TMP folder is available for writes? Also, check if the TMP environment variable is available.

[chrisrundlerfu]

Hi @karthiknadig

When I look at the permissions for the tmp directory in root it shows
lrwxr-xr-x@ 1 root admin 11 5 Dec 2019 tmp -> private/tmp
and so I looked at private/tmp and this shows
drwxrwxrwt 26 root wheel 832 10 Sep 07:54 tmp

I ran printenv which shows TMPDIR=/var/folders/w7/1qvx38910775sll063b2vg0w0000gn/T/ so I looked at permissions for var/folders
drwxr-xr-x 4 root wheel 128 7 Apr 17:19 folders
drwxr-xr-x@ 3 root wheel 96 7 Apr 17:19 w7
drwxr-xr-x@ 5 chrisrundle staff 160 7 Apr 17:19 1qvx38910775sll063b2vg0w0000gn
drwx------@ 407 chrisrundle staff 13024 10 Sep 08:50 T

In the /var/folders/w7/1qvx38910775sll063b2vg0w0000gn/T/ folder there are some files for vscode, like
srwxr-xr-x 1 chrisrundle staff 0 9 Sep 17:33 vscode-git-5c33030ebd.sock
drwxr-xr-x 3 chrisrundle staff 96 9 Sep 17:37 vscode-typescript501
but nothing called Untitled...

[qmg-drettie]

I get the same issue when formatting an unsaved file

[karthiknadig]

We have a prototype formatter that can handle this over Language Server Protocol. This means we don't have to create a temporary file to use with black. Please see here for the prototype and try it out. psf/black#2883

When trying out the prototype please disable formatting with the python extension by setting "python.formatting.provider": "none".

[karthiknadig]

Closing this in favor of #17918