Reproduction steps:
1. Open the attached “IN-103129“ project
2. Select the Android Build Platform and/or the Vulkan Graphics API
3. In the Project window, select the “Assets/Broken Shader_Vulkan_6_1_XRMotionVectorsFailCompilation_Test.shadergraph” asset
4. In the Inspector, press "Compile and show code"
5. Observe the Inspector
Expected result: No errors
Actual result: An “'undeclared identifier '_BaseMap_ST'“ error appears
Reproducible with: 6000.1.0a8, 6000.1.7f1, 6000.2.0b5
Not reproducible with: 2022.3.63f1, 6000.0.51f1, 6000.1.0a7
Reproducible environments: Windows 10 (by reporter), macOS 15.5
Not reproducible environments: No other environments tested