How to use metals to debug scala project with off-line (without internet)

[passion123]

Hi,while using theia(the browser-based vscode like IDE) to develop the scala project,i met an issue as below:
I deploy the theia on a server without internet,it alwasy showed the below error "Future timed out after",but on a server with internet it can be debugged successfully,Could any one meet this or give some advice on this ?
The logs as below：
Initializing Scala Debugger
2023.09.18 05:54:26 INFO Flyway Community Edition 8.5.8 by Redgate
2023.09.18 05:54:26 INFO See what's new here: https://flywaydb.org/documentation/learnmore/releaseNotes#8.5.8
2023.09.18 05:54:26 INFO
2023.09.18 05:54:26 INFO Database: jdbc:h2:file:/home/project/scala/tasks.metals/metals (H2 2.1)
2023.09.18 05:54:26 WARN Flyway upgrade recommended: H2 2.1.212 is newer than this version of Flyway and support has not been tested. The latest supported version of H2 is 2.1.210.
2023.09.18 05:54:26 INFO Successfully validated 3 migrations (execution time 00:00.018s)
2023.09.18 05:54:26 INFO Current version of schema "PUBLIC": 3
2023.09.18 05:54:26 INFO Schema "PUBLIC" is up to date. No migration necessary.
2023.09.18 05:54:26 INFO Attempting to connect to the build server...
2023.09.18 05:54:26 INFO skipping build import with status 'Installed'
2023.09.18 05:54:30 INFO tracing is disabled for protocol BSP, to enable tracing of incoming and outgoing JSON messages create an empty file at /home/project/ide-server/model-files/scala/169476583820368_tasks-1984/.metals/bsp.trace.json or /home/webide/.cache/metals/bsp.trace.json
2023.09.18 05:54:30 INFO time: Connected to build server in 3.9s
2023.09.18 05:54:30 INFO Connected to Build server: Bloop v1.5.0
2023.09.18 05:54:30 INFO time: Imported build in 0.16s
[Error - 5:56:18 AM] Request workspace/executeCommand failed.
Message: Internal error.
Code: -32603
java.util.concurrent.CompletionException: java.util.concurrent.TimeoutException: Future timed out after [60 seconds]
at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:292)
at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:308)
at java.util.concurrent.CompletableFuture.uniAccept(CompletableFuture.java:661)
at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:646)
at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1990)
at scala.concurrent.java8.FuturesConvertersImpl$CF.apply(FutureConvertersImpl.scala:29)
at scala.concurrent.java8.FuturesConvertersImpl$CF.apply(FutureConvertersImpl.scala:26)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:484)
at scala.concurrent.ExecutionContext$parasitic$.execute(ExecutionContext.scala:222)
at scala.concurrent.impl.Promise$Transformation.submitWithValue(Promise.scala:429)
at scala.concurrent.impl.Promise$DefaultPromise.submitWithValue(Promise.scala:338)
at scala.concurrent.impl.Promise$DefaultPromise.tryComplete0(Promise.scala:285)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:504)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:750)
Caused by: java.util.concurrent.TimeoutException: Future timed out after [60 seconds]
at scala.concurrent.impl.Promise$DefaultPromise.tryAwait0(Promise.scala:248)
at scala.concurrent.impl.Promise$DefaultPromise.result(Promise.scala:261)
at scala.concurrent.Await$.$anonfun$result$1(package.scala:201)
at scala.concurrent.BlockContext$DefaultBlockContext$.blockOn(BlockContext.scala:62)
at scala.concurrent.Await$.result(package.scala:124)
at scala.meta.internal.metals.MetalsEnrichments$XtensionScalaFuture.$anonfun$withTimeout$1(MetalsEnrichments.scala:203)
at scala.concurrent.Future$.$anonfun$apply$1(Future.scala:678)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:467)
... 3 more

[tgodzik]

Thanks for the question, we do download a bunch of thing on demand, which is why you are seeing those issues. We would need to prepare the workspace before like we do in https://github.com/scalameta/metals-gitpod-sample

There might be more things needed like expression evaluator, which is only downloaded if needed for a specific version of Scala.

We also have a special main class that can used (though expression eval is not added there due to omission):
https://github.com/scalameta/metals/blob/main/metals/src/main/scala/scala/meta/metals/DownloadDependencies.scala

One might doubt if having everything on demand is actually a good model, but we haven't thought of anything better currently since there is way to many different Scala versions we support and putting it all into a single place to download, would be quite heavy, though it's not totally out of the question if needed. Do let us know your use case, maybe we can help out.

[passion123]

thx for ur response. I create a docker container to package all things（theia，maven，jdk, etc.） needed on a server with internet and then deploy the docker to a server without internet,it shows the 'time out errror' as above.
And by the way, it seems the "metals.mavenScript" （“/usr/bin/mvn”） can not customize a self maven to avoid using an embedded mvnw script (the metals version is v1.16.0),i am not sure if the embedded mvnw script resulting in the 'indexing' status to time out .
Please let me know if u have some advice on this, i would be grateful for any help

[tgodzik]

can not customize a self maven to avoid using an embedded mvnw script (the metals version is v1.16.0)

I think this might be to the fact that when importing we download additional things such as sources via our own maven plugin 🤔

Maybe if you also download sources while connected to the internet that would work?

[passion123]

yes，i make sure all things needed are download successfully and the scala project also can be debugged successfully， but after deploying the docker container with nothing changed to the server without internet ，it will be time out as above. Is there any other way to customize a self maven without the "metals.mavenScript" for it seems ineffective?

[tgodzik]

Maven shouldn't be an issue really. Do you see any logs in .metals/metals.log actually? We don't really download anything new when running debug, but by an off chance maybe there some logs that don't get to the metals output.

You could also potentially set environment variable COURSIER_MODE=offline which should make things fail right away if it's not available locally.

[passion123]

Thx，it‘s solved