remove sourceroot flag from analysis_store file content (it's not deterministic)

Author: Blaine Freestone

src/main/scala/higherkindness/rules_scala/workers/zinc/compile/FilteredSetup.scala

@@ -0,0 +1,49 @@
+package sbt.internal.inc
+
+import xsbti.compile.{CompileOptions, MiniSetup}
+import java.nio.file.{Path, Paths}
+
+/**
+ * Zinc's MiniSetup contains scalacOptions which include the --sourceroot flag that references
+ * absolute sandbox paths. These paths are non-deterministic across builds because the sandbox
+ * directory changes (e.g., __sandbox/4/_main vs __sandbox/8/_main), making the analysis files
+ * non-deterministic.
+ *
+ * This class filters out the --sourceroot option from the scalacOptions to ensure deterministic
+ * analysis files.
+ *
+ * TODO: Consider if there's a better way to handle this upstream in Zinc
+ */
+object FilteredSetup {
+  private val sourcerootFlag = "--sourceroot"
+
+  def getFilteredSetup(setup: MiniSetup): MiniSetup = {
+    val options = setup.options()
+    
+    // Filter out the --sourceroot option and its value
+    val filteredScalacOptions = {
+      val originalOptions = options.scalacOptions()
+      val filtered = scala.collection.mutable.ArrayBuffer[String]()
+      
+      var i = 0
+      while (i < originalOptions.length) {
+        val option = originalOptions(i)
+        if (option == sourcerootFlag) {
+          // Skip both the flag and its value (next argument)
+          i += 2
+        } else {
+          filtered += option
+          i += 1
+        }
+      }
+      
+      filtered.toArray
+    }
+
+    // Create new CompileOptions with filtered scalac options
+    val newOptions = options.withScalacOptions(filteredScalacOptions)
+    
+    // Create new MiniSetup with filtered options
+    setup.withOptions(newOptions)
+  }
+}

src/main/scala/higherkindness/rules_scala/workers/zinc/compile/ZincRunner.scala

@@ -18,7 +18,7 @@ import net.sourceforge.argparse4j.impl.Arguments as Arg
 import net.sourceforge.argparse4j.inf.{ArgumentParserException, Namespace}
 import sbt.internal.inc.classpath.ClassLoaderCache
 import sbt.internal.inc.caching.ClasspathCache
-import sbt.internal.inc.{Analysis, AnalyzingCompiler, CompileFailed, FilteredInfos, FilteredRelations, IncrementalCompilerImpl, Locate, PlainVirtualFile, PlainVirtualFileConverter, ZincUtil}
+import sbt.internal.inc.{Analysis, AnalyzingCompiler, CompileFailed, FilteredInfos, FilteredRelations, FilteredSetup, IncrementalCompilerImpl, Locate, PlainVirtualFile, PlainVirtualFileConverter, ZincUtil}
 import scala.jdk.CollectionConverters.*
 import scala.util.Try
 import scala.util.control.NonFatal
@@ -336,14 +336,17 @@ object ZincRunner extends WorkerMain[ZincRunnerWorkerConfig] {
       )
     }
 
+    // Filter out non-deterministic --sourceroot paths from the setup
+    val filteredSetup = FilteredSetup.getFilteredSetup(compileResult.setup)
+
     val analysisStoreText = AnalysisUtil.getAnalysisStore(
       new File(pathString.substring(0, pathString.length() - 3) + ".text.gz"),
       true,
       readWriteMappers,
     )
 
-    analysisStoreText.set(AnalysisContents.create(resultAnalysis, compileResult.setup))
-    analysisStore.set(AnalysisContents.create(resultAnalysis, compileResult.setup))
+    analysisStoreText.set(AnalysisContents.create(resultAnalysis, filteredSetup))
+    analysisStore.set(AnalysisContents.create(resultAnalysis, filteredSetup))
 
     // create used deps
     val usedDeps =