gnu: vxl: Fix builds.

* gnu/packages/image-processing.scm (vxl)[arguments]<#:test-exclude>:
Add nonexistent test.
(vxl-1)[arguments]: Inherit from base package.

Change-Id: Ic89293a8dcba0f420f28e4945f9e68706c701af2

gnu/packages/image-processing.scm

@@ -1240,6 +1240,9 @@ programmatically.")
               ""))
            #t))))
     (build-system cmake-build-system)
+    (arguments
+     ;; Not an actual test, but is incorrectly generated by the build system.
+     (list #:test-exclude "vul_vul_test_driver"))
     (inputs
      (list libgeotiff libtiff libjpeg-turbo libpng zlib))
     (home-page "https://github.com/vxl/vxl/")
@@ -1274,10 +1277,12 @@ libraries designed for computer vision research and implementation.")
              (("add_subdirectory\\((tiff|png|jpeg|zlib|bzlib|geotiff)\\)")
               ""))))))
     (arguments
-     `(#:configure-flags
-       ;; Needed for itk-snap
-       (list "-DVNL_CONFIG_LEGACY_METHODS=ON"
-             "-DCMAKE_CXX_STANDARD=14")))))
+     (substitute-keyword-arguments (package-arguments vxl)
+      ((#:configure-flags flags)
+       #~(cons* ;; Needed for itk-snap
+                "-DVNL_CONFIG_LEGACY_METHODS=ON"
+                "-DCMAKE_CXX_STANDARD=14"
+                #$flags))))))
 
 (define-public insight-toolkit
   ;; For information about ITK remote modules, see: