This was mentioned in #441. Filing as an issue so we can track it.

The issue seems to be intermittent and is hard to replicate, so I tried a bunch of things and could finally replicate it using the following steps:

1. Open VSCode with the Harper extension disabled.
2. Open a file that harper-ls can lint like a Markdown file.
3. Enable the Harper extension.
4. Type anything in the file you opened and try to save it with ctrl+s.
5. Saving the file gets blocked indefinitely until you click "Skip" on the pop-up that shows up:
   

Some notes:

• The extension does not work (you get no diagnostics) even after you click on "Skip".
• Step 2 is important, the issue does not occur if you enable the extension while no files that harper-ls can lint is open.
• The harper-ls process that was spawned by the extension when it is activated in step 3 does not get terminated even after the extension is deactivated. The process instead, at least for my system, gets attached to systemd instead of VSCode.
• I'm not sure why this is happening or if this is the only way to replicate this issue.