Project 'subproject' is missing required source folder: 'linked-srcs' subproject

[AnqiHuangQiQi]

I saw a similar issue reported here.
salesforce/bazel-eclipse#491 (comment)

I'm trying the project-per-package option.

Basically when the project-per-package strategy is being used there should never be a linked-srcs or linked-test-srcs

Based on that, when I test on Eclipse, it was broken at the beginning.
Then I tried the Configure Build Path option and remove the entry with linked-src. It seems working.

Then I switched back to Vscode.
I tried many ways:

• Reload/Restart/Clean Language Server
• Removed the Bazel cache and
• Removed the Vscode workspace
• Cleanup the .classpath file.
• Cleanup all level settings.json for Vscode.
• Removed .eclipse/projects folder.

It's literally nowhere is using linked-src. I still keep getting this error
Project 'subproject' is missing required source folder: 'linked-srcs'.

Hi @guw I noticed that you are gonna continue the /bazel-eclipse work on your own fork.
Where could we ask question about bazel eclipse?
Thank you ahead!

[guw]

Here is fine or in Bazel Slack.
https://bazel.build/help

[AnqiHuangQiQi]

Thanks @guw . I have joined the #ide channel in the Bazel slack.

So far what I found about this issue:

From Eclipse Jdtls side -
This is the code generated the error:
ClasspathEntry.java

if (!projectPath.isPrefixOf(path) || JavaModel.getTarget(entry, true) == null){
return new JavaModelStatus(IJavaModelStatusConstants.INVALID_CLASSPATH, Messages.bind(Messages.classpath_unboundSourceFolder, new String[] {entryPathMsg, projectName}));
}

Call flow
validateClasspathEntry < ClasspathValidation.validate() / JavaModelManager.PerProjectInfo

JavaModelManager.getJavaModelManager().getPerProjectInfoCheckExistence(this.project);

From Bazel-Eclipse side - - Find out where does linked-src used BUT NOT CREATED.
ProjectPerPackageProvisioningStrategy
-> BaseProvisioningStrategy.configureRawClasspath
-> addSourceFolders
-> IPath dir : javaSourceInfo.getSourceDirectories()
-> var sourceFolder = dir.isEmpty() ? virtualSourceFolder : project.getProject().getFolder(dir);

dir is EMPTY
So virtualSourceFolder(linked-src) is used when calling

                    rawClasspath.add(
                        JavaCore.newSourceEntry(
                            sourceFolder.getFullPath(),

While nowhere created the linked-src folder.

Then I wondered why dir is EMPTY -
dir
<- javaSourceInfo.getSourceDirectories()
<- getSourceDirectoriesWithFilesOrGlobs**.keySet()** = sourceEntriesBySourceRoot
<- sourceEntriesBySourceRoot.put(sourceDirectory, list);
<- sourceDirectory = groupingByPotentialSourceRoots.apply(javaSourceFile);

If see a sample JavaSourceFile here:

BazelPackageLocation: Absolute path to the java file /.../src/main/java/com/a/b/c
detectedPackagePath: /com/a/b/c
relativePath: foo.java
relativePathParent: EMPTY String

And after groupingByPotentialSourceRoots.apply, the sourceDirectory is EMPTY String.
The key of sourceEntriesBySourceRoot is EMPTY String.

[guw]

Is there a BUILD file in src/main/java? That might explain this.

[AnqiHuangQiQi]

No. There is no BUILD file in src/main/java. com is the only folder in /java.
I checked how these paths are got.

By this relativizeLabelToPackageIfPossible function, it removed the whole path and only left the foo.java.
// drop the package name to identify a reference within package

Then getPotentialSourceDirectoryRoot
removed the last and only segment. That's why we got an Empty String
relativePathParent.removeLastSegments(detectedPackagePath.segmentCount());

BUILD file has this.
srcs = glob(["**/*.java"])

Target looks like
//someserver/src/main/java/com/a/b/c:c

And BUILD file is in this directory.
/someserver/src/main/java/com/a/b/c