From 1d6ec91dbc274b389b4f0d616752f36aec6f4ed8 Mon Sep 17 00:00:00 2001
From: eugene yokota <eed3si9n@gmail.com>
Date: Sun, 1 Mar 2026 05:28:43 -0500
Subject: [PATCH] [2.x] Fix lazy val name handling in Eval (#8818) (#8852)

Co-authored-by: kenji yoshida <6b656e6a69@gmail.com>
---
 buildfile/src/main/scala/sbt/internal/Eval.scala    |  6 ++++--
 .../sbt-test/project-load/lazy-val-name/build.sbt   | 13 +++++++++++++
 .../src/sbt-test/project-load/lazy-val-name/test    |  2 ++
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 sbt-app/src/sbt-test/project-load/lazy-val-name/build.sbt
 create mode 100644 sbt-app/src/sbt-test/project-load/lazy-val-name/test

diff --git a/buildfile/src/main/scala/sbt/internal/Eval.scala b/buildfile/src/main/scala/sbt/internal/Eval.scala
index 04befb995..4fa853dc8 100644
--- a/buildfile/src/main/scala/sbt/internal/Eval.scala
+++ b/buildfile/src/main/scala/sbt/internal/Eval.scala
@@ -19,6 +19,7 @@ import java.nio.file.{ Files, Path, Paths, StandardOpenOption }
 import java.security.MessageDigest
 import scala.jdk.CollectionConverters.*
 import scala.quoted.*
+import scala.reflect.NameTransformer
 import sbt.io.{ Hash, IO }
 
 /**
@@ -429,8 +430,9 @@ object Eval:
           vals ::= name.mangledString
         case tpd.ValDef(name, tpt, _) if name.is(NameKinds.LazyLocalName) =>
           val str = name.mangledString
-          val methodName = str.take(str.indexOf("$lzy"))
-          val m = tree.symbol.owner.requiredMethod(methodName.replace("$minus", "-"))
+          val methodName = str.take(str.indexOf(NameTransformer.LAZY_LOCAL_SUFFIX_STRING))
+          val decodedName = NameTransformer.decode(methodName)
+          val m = tree.symbol.owner.requiredMethod(decodedName)
           if isAcceptableType(m.info) then vals ::= methodName
         case t: tpd.Template   => this((), t.body)
         case t: tpd.PackageDef => this((), t.stats)
diff --git a/sbt-app/src/sbt-test/project-load/lazy-val-name/build.sbt b/sbt-app/src/sbt-test/project-load/lazy-val-name/build.sbt
new file mode 100644
index 000000000..76cf18d6b
--- /dev/null
+++ b/sbt-app/src/sbt-test/project-load/lazy-val-name/build.sbt
@@ -0,0 +1,13 @@
+lazy val `a + b` = "2.13.18"
+
+// https://github.com/scala/scala3/blob/3.8.2/library/src/scala/reflect/NameTransformer.scala#L47-L64
+lazy val ~=<>!#%^&|*/+-:\\?@ = "my-name"
+
+scalaVersion := `a + b`
+
+name := ~=<>!#%^&|*/+-:\\?@
+
+InputKey[Unit]("check") := {
+  assert(scalaVersion.value == "2.13.18")
+  assert(name.value == "my-name")
+}
diff --git a/sbt-app/src/sbt-test/project-load/lazy-val-name/test b/sbt-app/src/sbt-test/project-load/lazy-val-name/test
new file mode 100644
index 000000000..e3bd83da1
--- /dev/null
+++ b/sbt-app/src/sbt-test/project-load/lazy-val-name/test
@@ -0,0 +1,2 @@
+> compile
+> check