[cmake] remove fail-on-missing=OFF path for all dependencies that back opt-in features

README/ReleaseNotes/v642/index.md

@@ -40,6 +40,9 @@ The following people have contributed to this new version:
 ## Deprecation and Removal
 
 * The build options `vc`, `veccore`, `builtin_vc`, `builtin_veccore` and `rpath` that were deprecated are now removed and will result in configuration errors if used.
+* The option `fail-on-missing=OFF` is no longer honored for opt-in (ie OFF by default) build options requiring external dependencies such as `arrow`, `cocoa`, `daos`, `daos_mock`, `dcache`, `experimental_adaptivecpp`, `fcgi`, `fortran`, `gviz`, `mpi`, `pythia8`, `qt6web`, `tmva-cudnn`, `tmva-pymva`, `tmva-sofie`, `uring` or `vecgeom`. If the respective associated package dependency is not installed, ROOT will always raise a configuration error independent of the value of `fail-on-missing`. The user has to take action by either providing the dependency or manually disabling that option via `-Darrow=OFF`.
+  Note that `all=ON` enables several of these options, so building with `-Dall=ON` now requires all of their dependencies to be installed, or the unwanted ones to be disabled explicitly.
+  Build options that are enabled by default, such as `pyroot`, `opengl`, `xml`, `sqlite`, `davix`, `curl`, `tmva-cpu` or `tpython` are not affected: they are still disabled automatically when their dependencies are missing.
 * The method `RooRealVar::removeRange()` and the corresponding method in `RooErrorVar` that were deprecated in ROOT 6.40 are now removed.
 * The overloads of `RooAbsReal::createChi2()` and `RooAbsReal::chi2FitTo()` that take unbinned **RooDataSet** data objects were deprecated in ROOT 6.40 and are now removed.
 * The **RooStats::HybridPlot** class and the related **HybridResult::GetPlot** method were deprecated in ROOT 6.40 and are now removed.

cmake/modules/CheckCompiler.cmake

@@ -49,8 +49,8 @@ if(fortran)
       enable_language(Fortran)
     endif()
   endif()
-  if(NOT CMAKE_Fortran_COMPILER AND fail-on-missing)
-    message(FATAL_ERROR "No Fortran compiler found. Please make sure it's installed, or disable ROOT's Fortran features with '-Dfortran=OFF' (or set '-Dfail-on-missing=OFF' to automatically disable features with missing requirements)")
+  if(NOT CMAKE_Fortran_COMPILER)
+    message(SEND_ERROR "No Fortran compiler found. Please make sure it's installed, or disable ROOT's Fortran features with '-Dfortran=OFF'")
   endif()
 else()
   set(CMAKE_Fortran_COMPILER CMAKE_Fortran_COMPILER-NOTFOUND)

cmake/modules/SearchInstalledSoftware.cmake

@@ -478,12 +478,7 @@ if(gviz)
   message(STATUS "Looking for Graphviz")
   find_package(Graphviz)
   if(NOT GRAPHVIZ_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "Graphviz package not found and gviz option required")
-    else()
-      message(STATUS "Graphviz not found. Switching off gviz option")
-      set(gviz OFF CACHE BOOL "Disabled because Graphviz not found (${gviz_description})" FORCE)
-    endif()
+    message(SEND_ERROR "Graphviz libraries not found while -Dgviz=On.")
   endif()
 endif()
 
@@ -493,7 +488,7 @@ if(xml)
   find_package(LibXml2)
   if(NOT LIBXML2_FOUND)
     if(fail-on-missing)
-      message(SEND_ERROR "LibXml2 libraries not found and they are required (xml option enabled)")
+      message(SEND_ERROR "LibXml2 libraries not while -Dxml=ON")
     else()
       message(STATUS "LibXml2 not found. Switching off xml option")
       set(xml OFF CACHE BOOL "Disabled because LibXml2 not found (${xml_description})" FORCE)
@@ -544,12 +539,7 @@ if(fcgi)
   message(STATUS "Looking for FastCGI")
   find_package(FastCGI)
   if(NOT FASTCGI_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "FastCGI library not found and they are required (fcgi option enabled)")
-    else()
-      message(STATUS "FastCGI not found. Switching off fcgi option")
-      set(fcgi OFF CACHE BOOL "Disabled because FastCGI not found" FORCE)
-    endif()
+    message(SEND_ERROR "FastCGI library not found while -Dfcgi=On")
   endif()
 endif()
 
@@ -559,7 +549,7 @@ if(sqlite)
   find_package(Sqlite)
   if(NOT SQLITE_FOUND)
     if(fail-on-missing)
-      message(SEND_ERROR "SQLite libraries not found and they are required (sqlite option enabled)")
+      message(SEND_ERROR "SQLite libraries not found while -Dsqlite=ON")
     else()
       message(STATUS "SQLite not found. Switching off sqlite option")
       set(sqlite OFF CACHE BOOL "Disabled because SQLite not found (${sqlite_description})" FORCE)
@@ -572,12 +562,7 @@ if(pythia8)
   message(STATUS "Looking for Pythia8")
   find_package(Pythia8)
   if(NOT PYTHIA8_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "Pythia8 libraries not found and they are required (pythia8 option enabled)")
-    else()
-      message(STATUS "Pythia8 not found. Switching off pythia8 option")
-      set(pythia8 OFF CACHE BOOL "Disabled because Pythia8 not found (${pythia8_description})" FORCE)
-    endif()
+    message(SEND_ERROR "Pythia8 libraries not found while -Dpythia8=ON")
   endif()
 endif()
 
@@ -592,7 +577,7 @@ if(fftw3)
     find_package(FFTW)
     if(NOT FFTW_FOUND)
       if(fail-on-missing)
-        message(SEND_ERROR "FFTW3 libraries not found and they are required (fftw3 option enabled)")
+        message(SEND_ERROR "FFTW3 libraries not found while -Dfftw3=ON")
       else()
         message(STATUS "FFTW3 not found. Set [environment] variable FFTW_DIR to point to your FFTW3 installation")
         message(STATUS "                 Alternatively, you can also enable the option 'builtin_fftw3' to build FFTW3 internally'")
@@ -730,15 +715,8 @@ endif()
 if(arrow)
   find_package(Arrow)
   if(NOT ARROW_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "Apache Arrow not found. Please set ARROW_HOME to point to your Arrow installation, "
-                          "or include the installation of Arrow in the CMAKE_PREFIX_PATH.")
-    else()
-      message(STATUS "Apache Arrow API not found. Set variable ARROW_HOME to point to your Arrow installation, "
-                     "or include the installation of Arrow in the CMAKE_PREFIX_PATH.")
-      message(STATUS "For the time being switching OFF 'arrow' option")
-      set(arrow OFF CACHE BOOL "Disabled because Apache Arrow API not found (${arrow_description})" FORCE)
-    endif()
+    message(SEND_ERROR "Apache Arrow not found but is required. Please set ARROW_ROOT to point to your Arrow installation, "
+                          "or include the installation of Arrow in the CMAKE_PREFIX_PATH. Or disable option 'arrow'.")
   endif()
 
 endif()
@@ -747,13 +725,8 @@ endif()
 if(dcache)
   find_package(DCAP)
   if(NOT DCAP_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "dCap library not found and is required (dcache option enabled)")
-    else()
-      message(STATUS "dCap library not found. Set variable DCAP_DIR to point to your dCache installation")
-      message(STATUS "For the time being switching OFF 'dcache' option")
-      set(dcache OFF CACHE BOOL "Disabled because dCap not found (${dcache_description})" FORCE)
-    endif()
+    message(SEND_ERROR "dCap library not found while -Ddcache=ON"
+      " Set variable DCAP_ROOT to point to your dCache installation. Or disable option 'dcache'.")
   endif()
 endif()
 
@@ -827,12 +800,7 @@ if (uring)
     message(STATUS "Looking for liburing")
     find_package(liburing)
     if(NOT LIBURING_FOUND)
-      if(fail-on-missing)
-        message(SEND_ERROR "liburing not found and uring option required")
-      else()
-        message(STATUS "liburing not found. Switching off uring option")
-        set(uring OFF CACHE BOOL "Disabled because liburing was not found (${uring_description})" FORCE)
-      endif()
+      message(SEND_ERROR "liburing not found and uring option required. Install it on the system or disable option 'uring'.")
     endif()
   endif()
 endif()
@@ -846,28 +814,15 @@ if (testing AND NOT daos AND NOT WIN32)
 endif()
 
 if (daos OR daos_mock)
-  message(STATUS "Looking for libuuid")
-  if(fail-on-missing)
-    find_package(libuuid REQUIRED)
-  else()
-    find_package(libuuid)
-    if(NOT libuuid_FOUND)
-      message(STATUS "libuuid not found. Disabling DAOS support")
-      set(daos OFF CACHE BOOL "Disabled (libuuid not found)" FORCE)
-      set(daos_mock OFF CACHE BOOL "Disabled (libuuid not found)" FORCE)
-    endif()
+  find_package(libuuid)
+  if(NOT libuuid_FOUND)
+    message(SEND_ERROR "libuuid not found and it is required (daos or daos_mock option enabled). Install it on the system, or disable options 'daos' and 'daos_mock'")
   endif()
 endif()
 if (daos)
-  message(STATUS "Looking for DAOS")
-  if(fail-on-missing)
-    find_package(DAOS REQUIRED)
-  else()
-    find_package(DAOS)
-    if(NOT DAOS_FOUND)
-      message(STATUS "libdaos not found. Disabling DAOS support")
-      set(daos OFF CACHE BOOL "Disabled (libdaos not found)" FORCE)
-    endif()
+  find_package(DAOS)
+  if(NOT DAOS_FOUND)
+    message(SEND_ERROR "libdaos not found while -Ddaos=ON. Install it on the system, or disable option 'daos'")
   endif()
 endif()
 
@@ -957,15 +912,8 @@ endif()
 if (vecgeom)
   message(STATUS "Looking for VecGeom")
   find_package(VecGeom 1.2 CONFIG)
-  if(NOT VecGeom_FOUND )
-    if(fail-on-missing)
-      message(SEND_ERROR "VecGeom not found. Ensure that the installation of VecGeom is in the CMAKE_PREFIX_PATH")
-    else()
-      message(STATUS "VecGeom not found. Ensure that the installation of VecGeom is in the CMAKE_PREFIX_PATH")
-      message(STATUS "              example: CMAKE_PREFIX_PATH=<VecGeom_install_path>/lib/cmake/VecGeom")
-      message(STATUS "              For the time being switching OFF 'vecgeom' option")
-      set(vecgeom OFF CACHE BOOL "Disabled because VecGeom not found (${vecgeom_description})" FORCE)
-    endif()
+  if(NOT VecGeom_FOUND)
+    message(SEND_ERROR "VecGeom not found. Ensure that the installation of VecGeom is in the CMAKE_PREFIX_PATH, or disable 'vecgeom'")
   else()
     message(STATUS "   Found VecGeom " ${VecGeom_VERSION})
   endif()
@@ -1000,12 +948,7 @@ if(experimental_adaptivecpp)
     endfunction()
     message(STATUS "AdaptiveCpp sycl enabled")
   else()
-    if(fail-on-missing)
-      message(FATAL_ERROR "AdaptiveCpp library not found")
-    else()
-      message(STATUS "AdaptiveCpp library not found")
-      set(sycl OFF CACHE BOOL "Disabled because no SYCL implementation is not found" FORCE)
-    endif()
+    message(SEND_ERROR "AdaptiveCpp library not found, install it or disable 'experimental_adaptivecpp'")
   endif()
 endif()
 
@@ -1016,11 +959,9 @@ if(tmva-sofie)
     message(STATUS "Looking for BLAS as an optional testing dependency of TMVA-SOFIE")
     find_package(BLAS)
     if(NOT BLAS_FOUND)
-      if(fail-on-missing)
-        message(FATAL_ERROR "BLAS not found, but it's required for TMVA-SOFIE testing")
-      else()
-        message(WARNING "BLAS not found: TMVA-SOFIE will not be fully tested")
-      endif()
+      # BLAS only backs the TMVA-SOFIE tests, not the feature itself, so a
+      # missing BLAS must not turn into a configuration error.
+      message(WARNING "BLAS not found: TMVA-SOFIE will not be fully tested")
     endif()
   endif()
   message(STATUS "Looking for Protobuf")
@@ -1030,28 +971,13 @@ if(tmva-sofie)
     find_package(Protobuf MODULE)
   endif()
   if(NOT Protobuf_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "Protobuf libraries not found and they are required (tmva-sofie option enabled)")
-    else()
-      message(STATUS "Protobuf not found. Switching off tmva-sofie option")
-      set(tmva-sofie OFF CACHE BOOL "Disabled because Protobuf not found" FORCE)
-    endif()
+    message(SEND_ERROR "Protobuf libraries not found while -Dtmva-sofie=ON")
   else()
     if(Protobuf_VERSION LESS 3.0)
-      if(fail-on-missing)
-        message(SEND_ERROR "Protobuf libraries found but is less than the version required (3.0) (tmva-sofie option enabled)")
-      else()
-        message(STATUS "Protobuf found but its version is not high enough (>3.0). Switching off tmva-sofie option")
-        set(tmva-sofie OFF CACHE BOOL "Disabled because found Protobuf version is not enough" FORCE)
-      endif()
+      message(SEND_ERROR "Protobuf libraries found but is less than the version required (3.0) (tmva-sofie option enabled)")
     else()
       if(NOT TARGET protobuf::protoc)
-        if(fail-on-missing)
-          message(SEND_ERROR "Protobuf compiler not found (tmva-sofie option enabled)")
-        else()
-          message(STATUS "Protobuf compiler not found. Switching off tmva-sofie option")
-          set(tmva-sofie OFF CACHE BOOL "Disabled because Protobuf compiler not found" FORCE)
-        endif()
+        message(SEND_ERROR "Protobuf compiler not found  while -Dtmva-sofie=ON")
       endif()
     endif()
   endif()
@@ -1149,30 +1075,22 @@ if(tmva)
 
     ### Look for package CuDNN.
     if (tmva-cudnn)
-      if (fail-on-missing)
-        find_package(CUDNN REQUIRED)
-      else()
-        find_package(CUDNN)
-      endif()
+      find_package(CUDNN)
       if (CUDNN_FOUND)
         message(STATUS "CuDNN library found: " ${CUDNN_LIBRARIES})
         # Once proper cuDNN support in CMake, replace this with an alias target:
         add_library(ROOT::cuDNN SHARED IMPORTED)
         set_property(TARGET ROOT::cuDNN PROPERTY IMPORTED_LOCATION ${CUDNN_LIBRARIES})
         target_include_directories(ROOT::cuDNN INTERFACE ${CUDNN_INCLUDE_DIR})
       else()
-        message(STATUS "CuDNN library not found")
-        set(tmva-cudnn OFF CACHE BOOL "Disabled because cuDNN not found" FORCE)
+        message(SEND_ERROR "cudnn not found  while -Dtmva-cudnn=ON. Install it on the system, or disable option 'tmva-cudnn'")
       endif()
     endif()
   endif()
   if(tmva-pymva)
-    if(fail-on-missing AND (NOT Python3_NumPy_FOUND OR NOT Python3_Development_FOUND))
+    if(NOT Python3_NumPy_FOUND OR NOT Python3_Development_FOUND)
       message(SEND_ERROR "TMVA: numpy python package or Python development package not found and tmva-pymva component required"
                           " (python executable: ${Python3_EXECUTABLE})")
-    elseif(NOT Python3_NumPy_FOUND OR NOT Python3_Development_FOUND)
-      message(STATUS "TMVA: Numpy or Python development package not found for python ${Python3_EXECUTABLE}. Switching off tmva-pymva option")
-      set(tmva-pymva OFF CACHE BOOL "Disabled because Numpy or Python development package were not found (${tmva-pymva_description})" FORCE)
     endif()
   endif()
 else()
@@ -1218,15 +1136,8 @@ if (mpi)
   message(STATUS "Looking for MPI")
   find_package(MPI)
   if(NOT MPI_FOUND)
-    if(fail-on-missing)
-      message(SEND_ERROR "MPI not found. Ensure that the installation of MPI is in the CMAKE_PREFIX_PATH."
-        " Example: CMAKE_PREFIX_PATH=<MPI_install_path> (e.g. \"/usr/local/mpich\")")
-    else()
-      message(STATUS "MPI not found. Ensure that the installation of MPI is in the CMAKE_PREFIX_PATH")
-      message(STATUS "     Example: CMAKE_PREFIX_PATH=<MPI_install_path> (e.g. \"/usr/local/mpich\")")
-      message(STATUS "     For the time being switching OFF 'mpi' option")
-      set(mpi OFF CACHE BOOL "Disabled because MPI not found (${mpi_description})" FORCE)
-    endif()
+    message(SEND_ERROR "MPI not found. Ensure that the installation of MPI is in the CMAKE_PREFIX_PATH."
+      " Example: CMAKE_PREFIX_PATH=<MPI_install_path> (e.g. \"/usr/local/mpich\"). Or disable option 'mpi'")
   endif()
 endif()
 

gui/qt6webdisplay/CMakeLists.txt

@@ -11,13 +11,7 @@
 find_package(Qt6 COMPONENTS Core WebEngineCore WebEngineWidgets CONFIG)
 
 if(NOT Qt6_FOUND)
-  if(fail-on-missing)
-    message(FATAL_ERROR "Could NOT find Qt6 (WebEngineCore, WebEngineWidgets)")
-  else()
-    message(WARNING "Qt6 (WebEngineCore, WebEngineWidgets) not found, disabling option 'qt6web'")
-    set(qt6web OFF CACHE BOOL "Disabled because Qt6 not found" FORCE)
-    return()
-  endif()
+  message(SEND_ERROR "Could NOT find Qt6 (WebEngineCore, WebEngineWidgets), install missing packages on the system or disable option 'qt6web'")
 endif()
 
 set(CMAKE_AUTOMOC ON)