ENH: superbuild: avoid required find_package

Superbuild/CMake/External_boost.cmake

@@ -15,7 +15,6 @@ if(USE_SYSTEM_BOOST)
   # Required
   find_package ( Boost
     1.35.0
-    REQUIRED
     )
   # Optional components
   find_package ( Boost

Superbuild/CMake/External_curl.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup cURL ...")
 
 if(USE_SYSTEM_CURL)
-  find_package ( CURL REQUIRED )
+  find_package ( CURL )
   add_custom_target(${proj})
   message(STATUS "  Using cURL system version")
 else()

Superbuild/CMake/External_expat.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup expat ...")
 
 if(USE_SYSTEM_EXPAT)
-  find_package ( EXPAT REQUIRED )
+  find_package ( EXPAT )
   add_custom_target(${proj})
   message(STATUS "  Using expat system version")
 else()

Superbuild/CMake/External_fftw.cmake

@@ -7,7 +7,7 @@ message(STATUS "Setup FFTW ...")
 
 if(USE_SYSTEM_FFTW)
   # TODO : use ITK's FindFFTW
-  #find_package ( FFTW REQUIRED )
+  #find_package ( FFTW )
   add_custom_target(${proj})
   message(STATUS "  Using FFTW system version")
 else()

Superbuild/CMake/External_gdal.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup GDAL...")
 
 if(USE_SYSTEM_GDAL)
-  find_package ( GDAL REQUIRED )
+  find_package ( GDAL )
   add_custom_target(${proj})
   message(STATUS "  Using GDAL system version")
 else()

Superbuild/CMake/External_geos.cmake

@@ -7,7 +7,7 @@ message(STATUS "Setup GEOS ...")
 
 if(USE_SYSTEM_GEOS)
   # TODO : FindGEOS.cmake
-  #find_package ( GEOS REQUIRED )
+  #find_package ( GEOS )
   add_custom_target(${proj})
   message(STATUS "  Using GEOS system version")
 else()

Superbuild/CMake/External_geotiff.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup libgeotiff...")
 
 if(USE_SYSTEM_GEOTIFF)
-  find_package ( GeoTIFF REQUIRED )
+  find_package ( GeoTIFF )
   add_custom_target(${proj})
   message(STATUS "  Using libgeotiff system version")
 else()

Superbuild/CMake/External_itk.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup ITK...")
 
 if(USE_SYSTEM_ITK)
-  find_package ( ITK REQUIRED )
+  find_package ( ITK )
   add_custom_target(${proj})
   message(STATUS "  Using ITK system version")
 else()

Superbuild/CMake/External_jpeg.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup libjpeg...")
 
 if(USE_SYSTEM_JPEG)
-  find_package ( JPEG REQUIRED )
+  find_package ( JPEG )
   add_custom_target(${proj})
   message(STATUS "  Using libjpeg system version")
 else()

Superbuild/CMake/External_libkml.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup libKML ...")
 
 if(USE_SYSTEM_LIBKML)
-  find_package ( LibKML REQUIRED )
+  find_package ( LibKML )
   add_custom_target(${proj})
   message(STATUS "  Using libKML system version")
 else()

Superbuild/CMake/External_muparser.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup muParser ...")
 
 if(USE_SYSTEM_MUPARSER)
-  find_package ( MUPARSER REQUIRED )
+  find_package ( MUPARSER )
   add_custom_target(${proj})
   message(STATUS "  Using muParser system version")
 else()

Superbuild/CMake/External_muparserx.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup muParserX ...")
 
 if(USE_SYSTEM_MUPARSERX)
-  find_package ( MUPARSERX REQUIRED )
+  find_package ( MUPARSERX )
   add_custom_target(${proj})
   message(STATUS "  Using muParserX system version")
 else()

Superbuild/CMake/External_opencv.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup OpenCV...")
 
 if(USE_SYSTEM_OPENCV)
-  find_package ( OpenCV REQUIRED )
+  find_package ( OpenCV )
   add_custom_target(${proj})
   message(STATUS "  Using OpenCV system version")
 else()

Superbuild/CMake/External_openjpeg.cmake

@@ -7,7 +7,7 @@ message(STATUS "Setup OpenJpeg...")
 
 if(USE_SYSTEM_OPENJPEG)
   # TODO : FindOpenJPEG.cmake
-  # find_package ( OpenJPEG REQUIRED )
+  # find_package ( OpenJPEG )
   add_custom_target(${proj})
   message(STATUS "  Using OpenJpeg system version")
 else()

Superbuild/CMake/External_openthreads.cmake

@@ -10,7 +10,7 @@ set(USE_SYSTEM_OPENTHREADS OFF)
 endif()
 
 if(USE_SYSTEM_OPENTHREADS)
-  find_package ( OpenThreads REQUIRED )
+  find_package ( OpenThreads )
   add_custom_target(${proj})
   message(STATUS "  Using OpenThread system version")
 else()

Superbuild/CMake/External_ossim.cmake

@@ -14,7 +14,7 @@ message(STATUS "Setup Ossim...")
 ADD_SYSTEM_LOCATION(PROJECT ${proj} VARIABLES ${proj}_LIBRARY ${proj}_INCLUDE_DIR)
 
 if(USE_SYSTEM_OSSIM)
-  find_package ( Ossim REQUIRED )
+  find_package ( Ossim )
   add_custom_target(${proj})
   message(STATUS "  Using OSSIM system version")
 else()

Superbuild/CMake/External_pcre.cmake

@@ -7,7 +7,7 @@ message(STATUS "Setup pcre...")
 
 if(USE_SYSTEM_PCRE)
   # TODO : FindPCRE.cmake
-  # find_package ( PCRE REQUIRED )
+  # find_package ( PCRE )
   add_custom_target(${proj})
   message(STATUS "  Using pcre system version")
 else()

Superbuild/CMake/External_png.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup libpng...")
 
 if(USE_SYSTEM_PNG)
-  find_package ( PNG REQUIRED )
+  find_package ( PNG )
   add_custom_target(${proj})
   message(STATUS "  Using libpng system version")
 else()

Superbuild/CMake/External_proj.cmake

@@ -7,7 +7,7 @@ message(STATUS "Setup Proj.4 ...")
 
 if(USE_SYSTEM_PROJ)
   # TODO : FindPROJ.cmake
-  #find_package ( PROJ REQUIRED )
+  #find_package ( PROJ )
   add_custom_target(${proj})
   message(STATUS "  Using Proj4 system version")
 else()

Superbuild/CMake/External_qt4.cmake

@@ -6,7 +6,7 @@ set(__EXTERNAL_${proj}__ 1)
 message(STATUS "Setup Qt4 ...")
 
 if(USE_SYSTEM_QT4)
-  find_package ( QT4 REQUIRED )
+  find_package ( QT4 )
   add_custom_target(${proj})
   message(STATUS "  Using Qt4 system version")
 else()