From f3dd5dbd7138c66785e7ab61f6aeaa860c0f0935 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sun, 4 May 2025 17:22:08 -0400
Subject: [PATCH] fix: Fix qual lookup

**Problem**
Nested macro that expands to map or mapN fails to
find the qual because the trees end up being different
between the record scan and actual replacement.

**Solution**
First try for equals normally, then compare the show strings.
---
 .../main/scala/sbt/internal/util/appmacro/Cont.scala  | 10 +++++++++-
 sbt-app/src/sbt-test/project/nested-macro/build.sbt   | 11 +++++++++++
 sbt-app/src/sbt-test/project/nested-macro/test        |  1 +
 3 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 sbt-app/src/sbt-test/project/nested-macro/build.sbt
 create mode 100644 sbt-app/src/sbt-test/project/nested-macro/test

diff --git a/core-macros/src/main/scala/sbt/internal/util/appmacro/Cont.scala b/core-macros/src/main/scala/sbt/internal/util/appmacro/Cont.scala
index 87c21204d..8e773dd54 100644
--- a/core-macros/src/main/scala/sbt/internal/util/appmacro/Cont.scala
+++ b/core-macros/src/main/scala/sbt/internal/util/appmacro/Cont.scala
@@ -266,7 +266,15 @@ trait Cont:
                     (name: String, tpe: Type[x], qual: Term, oldTree: Term) =>
                       given Type[x] = tpe
                       convert[x](name, qual) transform { (replacement: Term) =>
-                        val idx = inputs.indexWhere(input => input.qual == qual)
+                        val idxEq = inputs.indexWhere(input => input.qual == qual)
+                        // use show to compare trees for Def.task comparison
+                        val idx =
+                          if idxEq < 0 then inputs.indexWhere(input => input.qual.show == qual.show)
+                          else idxEq
+                        if idx < 0 then
+                          sys.error(
+                            s"qual (${qual}) not found in ${inputs.map(_.qual)}"
+                          )
                         applyTuple(p0, br.inputTupleTypeRepr, idx)
                     }
                   val modifiedBody =
diff --git a/sbt-app/src/sbt-test/project/nested-macro/build.sbt b/sbt-app/src/sbt-test/project/nested-macro/build.sbt
new file mode 100644
index 000000000..a6d00c01d
--- /dev/null
+++ b/sbt-app/src/sbt-test/project/nested-macro/build.sbt
@@ -0,0 +1,11 @@
+lazy val a1 = settingKey[Boolean]("")
+
+scalaVersion := "3.6.4"
+a1 := true
+
+Compile / sourceGenerators += {
+  val _ = a1.value
+  Def.task {
+    Seq.empty[File]
+  }.taskValue
+}
diff --git a/sbt-app/src/sbt-test/project/nested-macro/test b/sbt-app/src/sbt-test/project/nested-macro/test
new file mode 100644
index 000000000..5df2af1f3
--- /dev/null
+++ b/sbt-app/src/sbt-test/project/nested-macro/test
@@ -0,0 +1 @@
+> compile