diff --git a/test/DebugInfo/ASTSection_linker.swift b/test/DebugInfo/ASTSection_linker.swift
index bf49622056913..fc6ff338dd37e 100644
--- a/test/DebugInfo/ASTSection_linker.swift
+++ b/test/DebugInfo/ASTSection_linker.swift
@@ -2,15 +2,15 @@
 
 // RUN: %empty-directory(%t)
 
-// RUN: %target-swift-frontend -c -sdk /fake/sdk/path -Xcc -DA -Xcc -DB -emit-module -o %t %S/ASTSection.swift -swift-version 4
+// RUN: %target-swift-frontend -c -Xcc -DA -Xcc -DB -emit-module -o %t %S/ASTSection.swift -swift-version 4
 // RUN: %swift-ide-test -test-CompilerInvocation-from-module -source-filename=%t/ASTSection.swiftmodule
 
 // Test the inline section mechanism.
-// RUN: %target-ld %t/ASTSection.o -sectcreate __DWARF __swift_ast %t/ASTSection.swiftmodule -o %t/ASTSection.dylib -dylib -lSystem -lobjc
+// RUN: %target-ld %t/ASTSection.o -sectcreate __DWARF __swift_ast %t/ASTSection.swiftmodule -o %t/ASTSection.dylib -dylib -L%sdk/usr/lib -lSystem -lobjc
 // RUN: %lldb-moduleimport-test -verbose %t/ASTSection.dylib | %FileCheck %s
 
 // Test the symbol table entry.
-// RUN: %target-ld %t/ASTSection.o -add_ast_path %t/ASTSection.swiftmodule -o %t/ASTSection.dylib -dylib -lSystem -lobjc
+// RUN: %target-ld %t/ASTSection.o -add_ast_path %t/ASTSection.swiftmodule -o %t/ASTSection.dylib -dylib -L%sdk/usr/lib -lSystem -lobjc
 // RUN: %lldb-moduleimport-test -verbose %t/ASTSection.dylib | %FileCheck %s
 
 // REQUIRES: OS=macosx
@@ -18,6 +18,6 @@
 // CHECK: - Swift Version: {{.+}}.{{.+}}
 // CHECK: - Compatibility Version: 4
 // CHECK: - Target: {{.+}}-{{.+}}-{{.+}}
-// CHECK: - SDK path: /fake/sdk/path{{$}}
+// CHECK: - SDK path: {{.*}}MacOS{{.*}}.sdk
 // CHECK: - -Xcc options: -working-directory {{.+}} -DA -DB
 // CHECK: Importing ASTSection... ok!
diff --git a/test/Driver/environment.swift b/test/Driver/environment.swift
index 4f49cb5ca7f31..bf5e60ded91a4 100644
--- a/test/Driver/environment.swift
+++ b/test/Driver/environment.swift
@@ -2,7 +2,7 @@
 // UNSUPPORTED: windows
 // Apple's "System Integrity Protection" makes this test fail on OS X.
 
-// RUN: %swift_driver -target x86_64-unknown-gnu-linux -L/foo/ -driver-use-frontend-path %S/Inputs/print-var.sh %s LD_LIBRARY_PATH | %FileCheck -check-prefix=CHECK${LD_LIBRARY_PATH+_LAX} %s
+// RUN: %swift_driver -sdk "" -target x86_64-unknown-gnu-linux -L/foo/ -driver-use-frontend-path %S/Inputs/print-var.sh %s LD_LIBRARY_PATH | %FileCheck -check-prefix=CHECK${LD_LIBRARY_PATH+_LAX} %s
 
 // CHECK: {{^/foo/:[^:]+/lib/swift/linux$}}
 // CHECK_LAX: {{^/foo/:[^:]+/lib/swift/linux}}
diff --git a/test/Driver/linker.swift b/test/Driver/linker.swift
index 1c47aa6f420cd..257172b735c17 100644
--- a/test/Driver/linker.swift
+++ b/test/Driver/linker.swift
@@ -1,18 +1,18 @@
 // Must be able to run xcrun-return-self.sh
 // REQUIRES: shell
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.9 %s 2>&1 > %t.simple.txt
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-macosx10.9 %s 2>&1 > %t.simple.txt
 // RUN: %FileCheck %s < %t.simple.txt
 // RUN: %FileCheck -check-prefix SIMPLE %s < %t.simple.txt
 
-// RUN: not %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.9 -static-stdlib %s 2>&1 | %FileCheck -check-prefix=SIMPLE_STATIC %s
+// RUN: not %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-macosx10.9 -static-stdlib %s 2>&1 | %FileCheck -check-prefix=SIMPLE_STATIC %s
 
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-ios7.1-simulator %s 2>&1 > %t.simple.txt
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-ios7.1-simulator %s 2>&1 > %t.simple.txt
 // RUN: %FileCheck -check-prefix IOS_SIMPLE %s < %t.simple.txt
 
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-tvos9.0-simulator %s 2>&1 > %t.simple.txt
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-tvos9.0-simulator %s 2>&1 > %t.simple.txt
 // RUN: %FileCheck -check-prefix tvOS_SIMPLE %s < %t.simple.txt
 
-// RUN: %swiftc_driver -driver-print-jobs -target i386-apple-watchos2.0-simulator %s 2>&1 > %t.simple.txt
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target i386-apple-watchos2.0-simulator %s 2>&1 > %t.simple.txt
 // RUN: %FileCheck -check-prefix watchOS_SIMPLE %s < %t.simple.txt
 
 // RUN: %swiftc_driver -driver-print-jobs -target x86_64-unknown-linux-gnu -Ffoo -Fsystem car -F cdr -framework bar -Lbaz -lboo -Xlinker -undefined %s 2>&1 > %t.linux.txt
@@ -76,7 +76,7 @@
 // RUN: touch %t/b.swiftmodule
 // RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.9 %s %t/a.o %t/a.swiftmodule %t/b.o %t/b.swiftmodule -o linker | %FileCheck -check-prefix LINK-SWIFTMODULES %s
 
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.10   %s > %t.simple-macosx10.10.txt
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-macosx10.10   %s > %t.simple-macosx10.10.txt
 // RUN: %FileCheck %s < %t.simple-macosx10.10.txt
 // RUN: %FileCheck -check-prefix SIMPLE %s < %t.simple-macosx10.10.txt
 
diff --git a/test/Driver/macabi-environment.swift b/test/Driver/macabi-environment.swift
index 156bd04879786..5a53a012f57e2 100644
--- a/test/Driver/macabi-environment.swift
+++ b/test/Driver/macabi-environment.swift
@@ -2,7 +2,7 @@
 
 // UNSUPPORTED: windows
 
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-ios13.0-macabi -sdk %S/../Inputs/clang-importer-sdk %s | %FileCheck -check-prefix=IOS13-MACABI %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-ios13.0-macabi -sdk %S/../Inputs/clang-importer-sdk %s | %FileCheck -check-prefix=IOS13-MACABI %s
 // IOS13-MACABI: bin/swift
 // IOS13-MACABI: -target x86_64-apple-ios13.0-macabi
 
@@ -19,7 +19,7 @@
 
 // Adjust iOS versions < 13.0 to 13.0 for the linker's sake.
 
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-ios12.0-macabi -sdk %S/../Inputs/clang-importer-sdk %s | %FileCheck -check-prefix=IOS12-MACABI %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-ios12.0-macabi -sdk %S/../Inputs/clang-importer-sdk %s | %FileCheck -check-prefix=IOS12-MACABI %s
 // IOS12-MACABI: bin/swift
 // IOS12-MACABI: -target x86_64-apple-ios12.0-macabi
 
@@ -40,7 +40,7 @@
 // ZIPPERED-VARIANT-OBJECT: bin/swift
 // ZIPPERED-VARIANT-OBJECT: -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi
 
-// RUN: %swiftc_driver -driver-print-jobs -emit-library -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi -module-name foo %s | %FileCheck -check-prefix=ZIPPERED-VARIANT-LIBRARY %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -emit-library -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi -module-name foo %s | %FileCheck -check-prefix=ZIPPERED-VARIANT-LIBRARY %s
 // ZIPPERED-VARIANT-LIBRARY: bin/swift
 // ZIPPERED-VARIANT-LIBRARY: -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi
 
@@ -48,7 +48,7 @@
 // ZIPPERED-VARIANT-LIBRARY: -platform_version macos 10.14.0 0.0.0 -platform_version mac-catalyst 13.0.0 0.0.0
 
 // Make sure we pass the -target-variant when creating the pre-compiled header.
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi -enable-bridging-pch -import-objc-header %S/Inputs/bridging-header.h %s | %FileCheck -check-prefix=ZIPPERED-VARIANT-PCH %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi -enable-bridging-pch -import-objc-header %S/Inputs/bridging-header.h %s | %FileCheck -check-prefix=ZIPPERED-VARIANT-PCH %s
 // ZIPPERED-VARIANT-PCH: bin/swift
 // ZIPPERED-VARIANT-PCH: -target x86_64-apple-macosx10.14 -target-variant x86_64-apple-ios13.0-macabi
 // ZIPPERED_VARIANT-PCH  -emit-pch
@@ -64,7 +64,7 @@
 // REVERSE-ZIPPERED-VARIANT-OBJECT: bin/swift
 // REVERSE-ZIPPERED-VARIANT-OBJECT: -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14
 
-// RUN: %swiftc_driver -driver-print-jobs -emit-library -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14 -module-name foo %s | %FileCheck -check-prefix=REVERSE-ZIPPERED-VARIANT-LIBRARY %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -emit-library -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14 -module-name foo %s | %FileCheck -check-prefix=REVERSE-ZIPPERED-VARIANT-LIBRARY %s
 // REVERSE-ZIPPERED-VARIANT-LIBRARY: bin/swift
 // REVERSE-ZIPPERED-VARIANT-LIBRARY: -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14
 
@@ -72,7 +72,7 @@
 // REVERSE-ZIPPERED-VARIANT-LIBRARY: -platform_version mac-catalyst 13.0.0 0.0.0 -platform_version macos 10.14.0
 
 // Make sure we pass the -target-variant when creating the pre-compiled header.
-// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14 -enable-bridging-pch -import-objc-header %S/Inputs/bridging-header.h %s | %FileCheck -check-prefix=REVERSE-ZIPPERED-VARIANT-PCH %s
+// RUN: %swiftc_driver -sdk "" -driver-print-jobs -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14 -enable-bridging-pch -import-objc-header %S/Inputs/bridging-header.h %s | %FileCheck -check-prefix=REVERSE-ZIPPERED-VARIANT-PCH %s
 // REVERSE-ZIPPERED-VARIANT-PCH: bin/swift
 // REVERSE-ZIPPERED-VARIANT-PCH: -target x86_64-apple-ios13.0-macabi -target-variant x86_64-apple-macosx10.14
 // REVERSE-ZIPPERED_VARIANT-PCH  -emit-pch
diff --git a/test/Driver/options-interpreter.swift b/test/Driver/options-interpreter.swift
index 723bc7de0554d..33741e30bc4c1 100644
--- a/test/Driver/options-interpreter.swift
+++ b/test/Driver/options-interpreter.swift
@@ -14,17 +14,17 @@
 // PARSE_STDLIB: -parse-stdlib
 
 
-// RUN: %swift_driver -### -target x86_64-apple-macosx10.9 -resource-dir /RSRC/ %s | %FileCheck -check-prefix=CHECK-RESOURCE-DIR-ONLY %s
+// RUN: %swift_driver -sdk "" -### -target x86_64-apple-macosx10.9 -resource-dir /RSRC/ %s | %FileCheck -check-prefix=CHECK-RESOURCE-DIR-ONLY %s
 // CHECK-RESOURCE-DIR-ONLY: # DYLD_LIBRARY_PATH=/RSRC/macosx{{$}}
 
-// RUN: %swift_driver -### -target x86_64-unknown-linux-gnu -resource-dir /RSRC/ %s | %FileCheck -check-prefix=CHECK-RESOURCE-DIR-ONLY-LINUX${LD_LIBRARY_PATH+_LAX} %s
+// RUN: %swift_driver -sdk "" -### -target x86_64-unknown-linux-gnu -resource-dir /RSRC/ %s | %FileCheck -check-prefix=CHECK-RESOURCE-DIR-ONLY-LINUX${LD_LIBRARY_PATH+_LAX} %s
 // CHECK-RESOURCE-DIR-ONLY-LINUX: # LD_LIBRARY_PATH=/RSRC/linux{{$}}
 // CHECK-RESOURCE-DIR-ONLY-LINUX_LAX: # LD_LIBRARY_PATH=/RSRC/linux{{$|:}}
 
-// RUN: %swift_driver -### -target x86_64-apple-macosx10.9 -L/foo/ %s | %FileCheck -check-prefix=CHECK-L %s
+// RUN: %swift_driver -sdk "" -### -target x86_64-apple-macosx10.9 -L/foo/ %s | %FileCheck -check-prefix=CHECK-L %s
 // CHECK-L: # DYLD_LIBRARY_PATH={{/foo/:[^:]+/lib/swift/macosx$}}
 
-// RUN: %swift_driver -### -target x86_64-apple-macosx10.9 -L/foo/ -L/bar/ %s | %FileCheck -check-prefix=CHECK-L2 %s
+// RUN: %swift_driver -sdk "" -### -target x86_64-apple-macosx10.9 -L/foo/ -L/bar/ %s | %FileCheck -check-prefix=CHECK-L2 %s
 // CHECK-L2: # DYLD_LIBRARY_PATH={{/foo/:/bar/:[^:]+/lib/swift/macosx$}}
 
 // RUN: env DYLD_LIBRARY_PATH=/abc/ SDKROOT=/sdkroot %swift_driver_plain -### -target x86_64-apple-macosx10.9 -L/foo/ -L/bar/ %s 2>&1 | %FileCheck -check-prefix=CHECK-L2-ENV %s 
@@ -60,7 +60,7 @@
 // CHECK-COMPLEX-DAG: DYLD_FRAMEWORK_PATH=/foo/:/bar/:/abc/{{$| }}
 // CHECK-COMPLEX-DAG: DYLD_LIBRARY_PATH={{/foo2/:/bar2/:[^:]+/lib/swift/macosx:/sdkroot/usr/lib/swift($| )}}
 
-// RUN: %swift_driver -### -target x86_64-unknown-linux-gnu -L/foo/ %s | %FileCheck -check-prefix=CHECK-L-LINUX${LD_LIBRARY_PATH+_LAX} %s
+// RUN: %swift_driver -sdk "" -### -target x86_64-unknown-linux-gnu -L/foo/ %s | %FileCheck -check-prefix=CHECK-L-LINUX${LD_LIBRARY_PATH+_LAX} %s
 // CHECK-L-LINUX: # LD_LIBRARY_PATH={{/foo/:[^:]+/lib/swift/linux$}}
 // CHECK-L-LINUX_LAX: # LD_LIBRARY_PATH={{/foo/:[^:]+/lib/swift/linux($|:)}}
 
diff --git a/test/lit.cfg b/test/lit.cfg
index eb10093d42f5b..511f4a3fcb89c 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -391,8 +391,8 @@ if kIsWindows:
                                                                            config.swift_test_options,
                                                                            config.swift_driver_test_options)) )
 else:
-    config.substitutions.append( ('%swift_driver', "env SDKROOT= %r %s %s %s" % (config.swift, mcp_opt, config.swift_test_options, config.swift_driver_test_options)) )
-    config.substitutions.append( ('%swiftc_driver', "env SDKROOT= %r -toolchain-stdlib-rpath %s %s %s" % (config.swiftc, mcp_opt, config.swift_test_options, config.swift_driver_test_options)) )
+    config.substitutions.append( ('%swift_driver', "env SDKROOT=%s %r %s %s %s" % (config.variant_sdk, config.swift, mcp_opt, config.swift_test_options, config.swift_driver_test_options)) )
+    config.substitutions.append( ('%swiftc_driver', "env SDKROOT=%s %r -toolchain-stdlib-rpath %s %s %s" % (config.variant_sdk, config.swiftc, mcp_opt, config.swift_test_options, config.swift_driver_test_options)) )
 config.substitutions.append( ('%sil-opt', "%r %s %s" % (config.sil_opt, mcp_opt, config.sil_test_options)) )
 config.substitutions.append( ('%sil-func-extractor', "%r %s" % (config.sil_func_extractor, mcp_opt)) )
 config.substitutions.append( ('%sil-llvm-gen', "%r %s" % (config.sil_llvm_gen, mcp_opt)) )