Only disable known-broken lane

eng/pipelines/templates/stages/vmr-build.yml

@@ -360,8 +360,6 @@ stages:
             targetOS: osx
             targetArchitecture: x64
 
-    # Cross builds are currently failing
-
         - template: ../jobs/vmr-build.yml
           parameters:
             buildName: Mariner_x64_Cross
@@ -376,19 +374,21 @@ stages:
             targetOS: linux
             targetArchitecture: x64
 
-        - template: ../jobs/vmr-build.yml
-          parameters:
-            buildName: Mariner_x64_Cross_arm64
-            isBuiltFromVmr: ${{ parameters.isBuiltFromVmr }}
-            vmrBranch: ${{ variables.VmrBranch }}
-            architecture: arm64
-            pool:
-              name: ${{ variables.defaultPoolName }}
-              demands: ${{ variables.defaultPoolDemandsLinux }}
-            container: ${{ variables.marinerArm64CrossContainer }}
-            crossRootFs: '/crossrootfs/arm64'
-            targetOS: linux
-            targetArchitecture: arm64
+      # Mariner x64->non-x64 builds are currently broken, see https://github.com/dotnet/source-build/issues/3698
+
+      # - template: ../jobs/vmr-build.yml
+      #   parameters:
+      #     buildName: Mariner_x64_Cross
+      #     isBuiltFromVmr: ${{ parameters.isBuiltFromVmr }}
+      #     vmrBranch: ${{ variables.VmrBranch }}
+      #     architecture: arm64
+      #     pool:
+      #       name: ${{ variables.defaultPoolName }}
+      #       demands: ${{ variables.defaultPoolDemandsLinux }}
+      #     container: ${{ variables.marinerArm64CrossContainer }}
+      #     crossRootFs: '/crossrootfs/arm64'
+      #     targetOS: linux
+      #     targetArchitecture: arm64
 
         - template: ../jobs/vmr-build.yml
           parameters: