Incorrect path for cache directories on windows

[johanneshardt]

Describe the bug

Seems that this issue (#2451) has resurfaced:

Steps to reproduce:

• Minimal install: I've removed, sbt, coursier and scala-cli (only Metals installed).
• Removed everything relevant in %APPDATA%, %USERPROFILE% (metals, ammonite, coursier, bloop folders etc.)
• Created a build.sbt with only scalaVersion := "3.3.0" and main.scala
• Set JAVA_HOME = C:\Program Files\OpenJDK\jdk-19.0.1
• Opened VS Code in that directory

The "null" folder is created as soon as metals starts, the "powershell" folder is created when clicking "import build' on the popup from metals.

Output when running ProjectDirectories.from() as described in #2451:

Setting env vars (COURSIER_BIN_DIR, COURSIER_CACHE, COURSIER_JVM_CACHE) as was recommended at some time in the past makes no difference for me. Building with scala-cli instead of sbt, by running scala-cli setup-ide . before opening VS Code makes no difference either.

This seems to be an issue with directories-jvm again (dirs-dev/directories-jvm#51, dirs-dev/directories-jvm#49), so I'm not sure what can be done on metals' side. Mostly posting this in case someone else runs into this and only finds #2451.

Expected behavior

No response

Operating system

Windows

Editor/Extension

VS Code

Version of Metals

v1.24.0

Extra context or search terms

No response

[tgodzik]

I wonder if in such case we should do a workaround and replace null with %APPDATA% value and resolving .cache on it. That's the expected place, right? Alternatively, we could try %APPDATA%/metals-config to not interfere with possible existing cache.

Not the pretties workaround, but should work for us. What do you think?

[tgodzik]

Alternatively, we could just return None if the directory starts with null/

[tgodzik]

Let's try #5595 -> at least we will not create the null directory

[johanneshardt]

Seems reasonable 👍

[tgodzik]

I changed the fix a bit, so do let us know if that is not fixed in the end.

[johanneshardt]

Yes, that seems to work on my PC. Reverting metals to 1.0.1 reintroduced the bug after a restart as well. Thanks for the fix!

[NoahELE]

I found that the issue persists to exist on Windows. Importing Metals build keeps creating null and PowerShell 7.4.5 folders under the project dir.

[tgodzik]

That's unexpected, but best to create new issue.

[NoahELE]

#6885

New issue created.