1The `-index-store-path` option is an Apple extension not available in our
2Clang. Make it opt-in by default.
3
4(It is assumed the `target.type == test` check is for Xcode support, because
5there is no evidence of it in swift-corelibs-xctest.)
6
7--- a/Sources/Build/BuildPlan.swift
8+++ b/Sources/Build/BuildPlan.swift
9@@ -103,14 +103,7 @@ extension BuildParameters {
10 case .off:
11 addIndexStoreArguments = false
12 case .auto:
13- if configuration == .debug {
14- addIndexStoreArguments = true
15- } else if target.type == .test {
16- // Test discovery requires an index store for the test target to discover the tests
17- addIndexStoreArguments = true
18- } else {
19 addIndexStoreArguments = false
20- }
21 }
22
23 if addIndexStoreArguments {