metals sbt xdg specification

[tgodzik]

Discussed in #5775

^{Originally posted by untainsYD October 21, 2023}
When I import an sbt build in metals (Linux 6.5.8-arch1-1/VSCode), it creates a ~/.sbt folder in the home directory, ignoring the XDG specification. Even though I have set SBT_OPTS in .zprofile as follows, it is still being ignored:

export SBT_OPTS="$SBT_OPTS \
    -Dsbt.ivy.home=$XDG_CACHE_HOME/ivy \
    -Dsbt.boot.directory=$XDG_CACHE_HOME/sbt/boot \
    -Dsbt.preloaded=$XDG_CACHE_HOME/sbt/preloaded \
    -Dsbt.global.base=$XDG_CACHE_HOME/sbt \
    -Dsbt.global.staging=$XDG_CACHE_HOME/sbt/staging \
    -Dsbt.global.zinc=$XDG_CACHE_HOME/sbt/zinc \
    -Dsbt.dependency.base=$XDG_CACHE_HOME/sbt/dependency \
    -Dsbt.repository.config=$XDG_CONFIG_HOME/sbt/repositories \
    -Dsbt.global.settings=$XDG_CONFIG_HOME/sbt/global \
    -Dsbt.global.plugins=$XDG_CONFIG_HOME/sbt/plugins \
    -Dmaven.repo.local=$XDG_CACHE_HOME/maven/repository \
    -Divy.settings.dir=$XDG_CONFIG_HOME/ivy2 \
    -Divy.home=$XDG_CACHE_HOME/ivy2 \
    -Divy.cache.dir=$XDG_CACHE_HOME/ivy2/cache"

I have configured the Custom sbt launcher to propagate environment variables, but it doesn't seem to be effective.

> ls -lah ~/.sbt/boot
Permissions Size User      Group     Date Modified Name
drwxr-xr-x     - untainsYD untainsYD 21 Oct 23:27   scala-2.12.18
.rw-r--r--     0 untainsYD untainsYD 21 Oct 23:39   sbt.boot.lock
.rw-r--r--     0 untainsYD untainsYD 21 Oct 23:27   update.log

How can i force metals sbt to start the server in order to my SBT_OPTS?

[untainsYD]

If you will need an sbt file or smth like that, just mention me.

[kasiaMarek]

The issue seems to be the bsp config generated by sbt (.bsp/sbt.json). The args for starting the server are:

[some-path]/java -Xms100m -Xmx100m -classpath [some-path]/sbt-launch.jar -Dsbt.script=[some-path]/sbt xsbt.boot.Boot -bsp

Which will work if -Dsbt.boot.directory=... is added explicitly but won't pick up sbt opts. I feel like maybe sbt should pass those options when generating the config.

If one manually adds this option to args in .bsp/sbt.json it will work as expected, the problem is that sbt regenerates .bsp/sbt.json a lot, so this would have to be fixed constantly.

In metals we could insert such options when we start the sbt server, but that would work under the assumption that we know how the command for starting the server looks like, which is suboptimal, since metals should be oblivious to such things.

[tgodzik]

Shouldn't the environment variable work though? We start the process, so maybe we must make sure these variables are passed to sbt? We can suggest to restart if they changed.

[tgodzik]

It seems that it's not possible to fix this while launching via launcher, instead we should check if sbt is available on PATH and use it. For most advanced users it should be on the PATH.

Alternatively, you should be able to specify path to sbt by hand in the settings and it should work. (to be checked)

[kasiaMarek]

@untainsYD did setting sbt script in metals settings actually solved the issue for you?

[github-actions]

This issue was closed because no new information was added for the last 30 days. If you have any relevant information, feel free to add it and reopen the issue.

[untainsYD]

@untainsYD did setting sbt script in metals settings actually solved the issue for you?

No, it didn't, i have sbt option set, but nothing changed

It always recreates ~/.sbt folder in home directory.

[tgodzik]

Looks like maybe the env variable is not forwarded to Metals. Might be useful to start VS Code using code command from console. We should be forwarding the environment variable correctly otherwise 🤔

[kasiaMarek]

I don't think it will work right now. So it seems that starting sbt server using.../java ... xsbt.boot.Boot -bsp causes .sbt to be created (one would have to pass Dsbt.boot.directory= arg to it). This command isn't generated by Metals but by sbt via sbt bspConfig command, so an upstream fix seems to be needed here. Here is the sbt issue sbt/sbt#7469.