root-project · ferdymercury · Aug 18, 2026 · Aug 18, 2026 · Aug 18, 2026 · Aug 18, 2026
@@ -4,9 +4,11 @@ ccache=ON
 builtin_civetweb=ON
 builtin_vdt=ON
 ccache=ON
+daos_mock=ON
 fail-on-missing=ON
 minimal=ON
 roottest=ON
 testing=ON
+vdt=ON
 LSAN_OPTIONS=verbosity=1:log_threads=1
 ROOT_CTEST_CUSTOM_FLAGS=-E \(gtest-core-metacling-TClingTest$\|roottest-cling-specialobj-runf02$\|roottest-root-collection-DeleteWarning$\|roottest-root-io-evolution-fixarr2$\|roottest-root-meta-rlibmap$\|roottest-root-tree-cloning-runtreeCloneTest2$\|roottest-root-treeproxy-vectorint-vectorint$\)
@@ -1,7 +1,9 @@
 ccache=ON
 builtin_civetweb=ON
 builtin_vdt=ON
+daos_mock=ON
 fail-on-missing=ON
 minimal=ON
 roottest=ON
 testing=ON
+vdt=ON
@@ -39,6 +39,7 @@ coverage=OFF
 cuda=OFF
 curl=ON
 daos=OFF
+daos_mock=ON
 dataframe=ON
 davix=ON
 dcache=OFF
@@ -84,6 +85,7 @@ test_distrdf_pyspark=ON
 test_roofit_hs3testsuite=ON
 test_tmva_sofie=ON
 testing=ON
+testsupport=OFF
 tmva-cpu=ON
 tmva-gpu=OFF
 tmva-cudnn=OFF

@@ -21,5 +21,6 @@ builtin_zstd=ON
 check_connection=ON
 cocoa=ON
 davix=OFF
+libcxx=ON
 minuit2_omp=OFF
 x11=OFF
@@ -23,6 +23,7 @@ builtin_xxhash=ON
 builtin_zstd=ON
 cocoa=ON
 davix=OFF
+libcxx=ON
 minuit2_omp=OFF
 test_distrdf_dask=OFF
 test_distrdf_pyspark=OFF

@@ -20,5 +20,6 @@ builtin_xxhash=ON
 builtin_zstd=ON
 cocoa=ON
 davix=OFF
+libcxx=ON
 minuit2_omp=OFF
 x11=OFF
@@ -21,5 +21,6 @@ builtin_zstd=ON
 check_connection=ON
 cocoa=ON
 davix=OFF
+libcxx=ON
 minuit2_omp=OFF
 x11=OFF
@@ -19,6 +19,7 @@ builtin_xxhash=ON
 builtin_zlib=ON
 builtin_zstd=ON
 ccache=OFF
+daos_mock=OFF
 davix=OFF
 fortran=OFF
 llvm13_broken_tests=OFF

@@ -120,7 +120,7 @@
      matrix:
        # Specify platform + optional build option overrides
        # Build options: https://root.cern/install/build_from_source/#all-build-options
        platform: [mac26, mac27, mac-beta]
        arch: [ARM64]
        include:
          - platform: mac15
@@ -132,7 +132,7 @@
      - self-hosted
      - ${{ matrix.platform }}

    name: |
      ${{ matrix.platform }} ${{ matrix.arch }}
      ${{ (github.event_name != 'schedule' && github.event_name != 'workflow_dispatch' && join( matrix.overrides, ', ' )) || '' }}

@@ -151,8 +151,8 @@
        if: github.event_name == 'pull_request'
        env:
          GITHUB_PR_ORIGIN: ${{ github.event.pull_request.head.repo.clone_url }}
          OVERRIDES: ${{ join( matrix.overrides, ' ') }}
        run: |
          [ -d "${VIRTUAL_ENV_DIR}" ] && source ${VIRTUAL_ENV_DIR}/bin/activate
          echo "Python is now $(which python3) $(python3 --version)"
          src/.github/workflows/root-ci-config/build_root.py  \
@@ -402,7 +402,7 @@
           - image: alma10
           - image: ubuntu22
             python_venv: "/py-venv-3.12/ROOT-CI"
-            overrides: ["imt=Off", "CMAKE_BUILD_TYPE=Debug"]
+            overrides: ["imt=Off", "tmva-cpu=OFF", "CMAKE_BUILD_TYPE=Debug"]
           - image: ubuntu2404
             overrides: ["CMAKE_BUILD_TYPE=Debug"]
           - image: ubuntu2604

@@ -98,7 +98,7 @@ jobs:
 
     - name: Apply option overrides
       env:
-        OVERRIDES: "testing=Off roottest=Off"
+        OVERRIDES: "testing=Off", "roottest=Off", "daos_mock=Off"
         CONFIGFILE: '.github/workflows/root-ci-config/buildconfig/alma9.txt'
       shell: bash
       run: |

@@ -46,6 +46,7 @@ The following people have contributed to this new version:
   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 option `fail-on-missing=OFF` will no longer be honored for CMake ROOT build options that have easy-to-install dependencies (e.g. via homebrew or apt-get), such as those required by options `cfitsio`, `civetweb`, `fftw3`, `imt`, `mathmore`, `nlohmann_json`, `tmva-cpu`, `unuran`, `vdt` or `xrootd`. Before, associated `builtin_option` was automatically turned ON (or the opt-in feature turned to OFF), now, user has to install system package or manually set `builtin_option` to `ON` or opt-in feature to `OFF`.
+* Irrespective of the value of `fail-on-missing`, all ROOT build options that are contradictory or are missing a dependency will now raise an error rather than letting the build system to automatically turn features OFF or ON. A helpful error message will be printed stating what packages need to be installed or what build flags need to be changed.
 * The use of `CINT`-like implicit declarations such as `i = 0` is deprecated since [ROOT 6.32](https://root.cern/doc/v632/release-notes.html#deprecation-and-removal) and emits warnings `declaration without the 'auto' keyword is deprecated`. ROOT 6.44 will be the last release to support this syntax, after ROOT 6.44, the warning will turn into an error. Update those declarations by explicitly using the `auto` keyword: `auto i = 0`.
 * The legacy evaluation backend of RooFit and the related `RooFit::BatchMode()` command argument are deprecated and will be removed in ROOT 6.44. See the RooFit section below for details.
 * The method `RooRealVar::removeRange()` and the corresponding method in `RooErrorVar` that were deprecated in ROOT 6.40 are now removed.

@@ -51,6 +51,8 @@ if(fortran)
   endif()
   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'")
+    list(APPEND MISSING_PACKAGES 'gfortran')
+    list(APPEND HOTFIX_BUILD_FLAGS -Dfortran=OFF)
   endif()
 else()
   set(CMAKE_Fortran_COMPILER CMAKE_Fortran_COMPILER-NOTFOUND)
@@ -205,8 +207,8 @@ endif()
 if(libcxx)
   CHECK_CXX_COMPILER_FLAG("-stdlib=libc++" HAS_LIBCXX11)
   if(NOT HAS_LIBCXX11)
-    message(STATUS "Current compiler does not support -stdlib=libc++ option. Switching OFF libcxx option")
-    set(libcxx OFF CACHE BOOL "" FORCE)
+    message(SEND_ERROR "Current compiler ${CMAKE_CXX_COMPILER_ID} does not support -stdlib=libc++ option. Install compatible compiler or set -Dlibcxx=OFF")
+    list(APPEND HOTFIX_BUILD_FLAGS -Dlibcxx=OFF)
   endif()
 endif()
 

@@ -123,6 +123,7 @@ ROOT_BUILD_OPTION(coverage OFF "Enable compile flags for coverage testing")
 ROOT_BUILD_OPTION(cuda OFF "Enable support for CUDA (requires CUDA toolkit >= 7.5)")
 ROOT_BUILD_OPTION(curl ON "Enable support for HTTP(S) through libcurl")
 ROOT_BUILD_OPTION(daos OFF "Enable RNTuple support for Intel DAOS")
+ROOT_BUILD_OPTION(daos_mock OFF "Use libdaos_mock for RNTuple, use only for testing. Mutually exclusive with daos")
 ROOT_BUILD_OPTION(dataframe ON "Enable ROOT RDataFrame")
 ROOT_BUILD_OPTION(davix ON "Enable support for Davix (HTTP/WebDAV access)")
 ROOT_BUILD_OPTION(dcache OFF "Enable support for dCache (requires libdcap from DESY)")
@@ -158,14 +159,14 @@ ROOT_BUILD_OPTION(roofit ON "Build the advanced fitting package RooFit, and RooS
 ROOT_BUILD_OPTION(root7 ON "Build ROOT 7 experimental components of ROOT")
 ROOT_BUILD_OPTION(runtime_cxxmodules ON "Enable runtime support for C++ modules")
 ROOT_BUILD_OPTION(shadowpw OFF "Enable support for shadow passwords")
-ROOT_BUILD_OPTION(shared ON "Use shared 3rd party libraries if possible")
+ROOT_BUILD_OPTION(shared ON "Use shared 3rd party libraries if possible (OFF not supported on Windows)")
 ROOT_BUILD_OPTION(soversion OFF "Set version number in sonames for shared libraries. Not recommended, as the pcm and rootmap files do not (yet) support versioning and always point to the non-versioned shared libraries.")
 ROOT_BUILD_OPTION(spectrum ON "Enable support for TSpectrum")
 ROOT_BUILD_OPTION(sqlite ON "Enable support for SQLite")
 ROOT_BUILD_OPTION(ssl ON "Enable support for SSL encryption via OpenSSL")
 ROOT_BUILD_OPTION(test_distrdf_dask OFF "Enable distributed RDataFrame tests that use dask")
 ROOT_BUILD_OPTION(test_distrdf_pyspark OFF "Enable distributed RDataFrame tests that use pyspark")
-ROOT_BUILD_OPTION(testsupport OFF "Build the ROOT::TestSupport library required to use all features of ROOT_ADD_GTEST and similar macros (requires gtest at build time)")
+ROOT_BUILD_OPTION(testsupport OFF "Build the ROOT::TestSupport library required to use ROOT_ADD_GTEST and similar macros by downstream users (requires gtest at build time). Even if OFF, this library is still built if testing=ON")
 ROOT_BUILD_OPTION(thisroot_scripts ON "Build scripts like thisroot.{sh, fish, etc.} that set environment paths for using ROOT. Usually not needed when building ROOT for the distribution with a package manager.")
 ROOT_BUILD_OPTION(tmva ON "Build TMVA multi variate analysis library")
 ROOT_BUILD_OPTION(tmva-cpu ON "Build TMVA with CPU support for deep learning (requires BLAS)")
@@ -191,11 +192,11 @@ option(clingtest "Enable cling tests (Note: that this makes llvm/clang symbols v
 option(fail-on-missing "Fail at configure time if a required package cannot be found" OFF)
 option(gminimal "Enable only required options by default, but include X11/Cocoa" OFF)
 option(minimal "Enable only required options by default" OFF)
-option(rootbench "Build rootbench if rootbench exists in root or if it is a sibling directory (implies testing=ON)" OFF)
-option(roottest "Build roottest (implies testing=ON)" OFF)
+option(rootbench "Build rootbench if rootbench exists in root or if it is a sibling directory (requires testing=ON)" OFF)
+option(roottest "Build roottest (requires testing=ON)" OFF)
 option(test_roofit_hs3testsuite "Setup and use the HS3 conformance test suite (requires network)" OFF)
 option(test_tmva_sofie "Enable SOFIE tests (requires BLAS library that can be found with CMake's FindBLAS)" ON)
-option(testing "Enable testing with CTest" OFF)
+option(testing "Enable testing with CTest and GTest" OFF)
 option(asan "Build ROOT with address sanitizer instrumentation (see core/sanitizer for details)" OFF)
 option(_wheel_build "ROOT is being packaged as a wheel, do not install .dist-info metadata" OFF)
 
@@ -300,13 +301,20 @@ if(WIN32)
 elseif(APPLE)
   set(cocoa_defvalue ON)
   set(x11_defvalue OFF)
+  if(${CMAKE_CXX_COMPILER_ID} MATCHES Clang)
+    set(libcxx_defvalue ON)
+  endif()
 endif()
 
 # builtin_openssl is only supported on macOS
 if(builtin_openssl AND NOT APPLE)
     message(FATAL_ERROR ">>> Option 'builtin_openssl' is only supported on macOS.")
 endif()
 
+if(WIN32 AND NOT shared)
+  message(FATAL_ERROR "Option \"shared=Off\" not supported on Windows!")
+endif()
+
 #---Options depending of CMake Generator-------------------------------------------------------
 if( CMAKE_GENERATOR STREQUAL Ninja)
    set(fortran_defvalue OFF)
@@ -334,45 +342,122 @@ endif()
 #---Define at moment the options with the selected default values------------------------------
 ROOT_APPLY_OPTIONS()
 
-#---roottest option implies testing
-if(roottest OR rootbench)
-  set(testing ON CACHE BOOL "" FORCE)
+if(APPLE AND ${CMAKE_CXX_COMPILER_ID} MATCHES Clang)
+  if (NOT libcxx)
+    message(SEND_ERROR "libcxx=ON is needed for Clang compilers on Apple")
+    list(APPEND HOTFIX_BUILD_FLAGS -Dlibcxx=ON)
+  endif()
 endif()
 
-#---testing implies testsupport
-if(testing)
-  set(testsupport ON CACHE BOOL "" FORCE)
+# builtins require feature
+if (builtin_fftw3 AND NOT fftw3)
+  message(SEND_ERROR "-Dbuiltin_fftw3=ON requires -Dfftw3=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dfftw3=ON)
+endif()
+if (builtin_xrootd AND NOT xrootd)
+  message(SEND_ERROR "-Dbuiltin_xrootd=ON requires -Dxrootd=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dxrootd=ON)
+endif()
+if (builtin_cfitsio AND NOT fitsio)
+  message(SEND_ERROR "-Dbuiltin_cfitsio=ON requires -Dfitsio=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dfitsio=ON)
+endif()
+if (builtin_gl2ps AND NOT opengl)
+  message(SEND_ERROR "-Dbuiltin_gl2ps=ON requires -Dopengl=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dopengl=ON)
+endif()
+if (builtin_ftgl AND NOT opengl)
+  message(SEND_ERROR "-Dbuiltin_ftgl=ON requires -Dopengl=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dopengl=ON)
+endif()
+if (builtin_tbb AND NOT imt)
+  message(SEND_ERROR "-Dbuiltin_tbb=ON requires -Dimt=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dimt=ON)
+endif()
+if (builtin_vdt AND NOT vdt)
+  message(SEND_ERROR "-Dbuiltin_vdt=ON requires -Dvdt=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dvdt=ON)
+endif()
+if (builtin_gtest AND NOT (testing OR testsupport))
+  message(SEND_ERROR "-Dbuiltin_gtest=ON requires -Dtesting=ON or -Dtestsupport=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dtestsupport=ON)
+endif()
+if(builtin_openui5 AND NOT webgui)
+  message(SEND_ERROR "-Dbuiltin_openui5=ON requires -Dwebgui=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dwebgui=ON)
+endif()
+if (builtin_openssl AND NOT ssl)
+  message(SEND_ERROR "-Dbuiltin_openssl=ON requires -Dssl=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dssl=ON)
+endif()
+# On Linux, OpenGL should be working only with x11
+if(NOT WIN32 AND NOT APPLE)
+  if(opengl AND NOT x11)
+    message(SEND_ERROR "OpenGL requires x11 on Linux, either disable opengl or set -Dx11=ON")
+    list(APPEND HOTFIX_BUILD_FLAGS -Dopengl=OFF)
+  endif()
+endif()
+#---Check for Cocoa/Quartz graphics backend (MacOS X only)---------------------------
+# Note that this check happens *after* the above check for FreeType because that
+# library is needed for builds on Apple with Cocoa graphics
+if(cocoa)
+  if(APPLE)
+    if (x11)
+      message(SEND_ERROR "x11 (${x11_description}) and cocoa cannot be enabled simultaneously. Set -Dcocoa=OFF")
+      list(APPEND HOTFIX_BUILD_FLAGS -Dcocoa=OFF)
+    endif()
+  else()
+    message(SEND_ERROR "Cocoa option can only be enabled on MacOSX platform. Set -Dcocoa=OFF")
+    list(APPEND HOTFIX_BUILD_FLAGS -Dcocoa=OFF)
+  endif()
+elseif(asimage AND NOT x11 AND NOT WIN32)
+  message(SEND_ERROR "asimage on Unix requires x11, either disable asimage or set -Dx11=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dasimage=OFF)
 endif()
 
-#---ensure that the cuda option is sound
-if(cuda AND NOT CMAKE_CUDA_COMPILER)
-  message(FATAL_ERROR "Option cuda=On, but CMAKE_CUDA_COMPILER='${CMAKE_CUDA_COMPILER}'")
+#---roottest/rootbench options require testing
+if (roottest AND NOT testing)
+  message(SEND_ERROR "-Droottest=ON requires -Dtesting=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dtesting=ON)
+endif()
+if (rootbench AND NOT testing)
+  message(SEND_ERROR "-Drootbench=ON requires -Dtesting=ON")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dtesting=ON)
 endif()
 
 #---running HS3 test suite requires both testing and pyroot, but testing globally disables tests
 if(testing AND test_roofit_hs3testsuite AND NOT pyroot)
-  message(FATAL_ERROR "-Dtest_roofit_hs3testsuite=ON requires both -Dtesting=ON and -Dpyroot=ON)")
+  message(SEND_ERROR "-Dtest_roofit_hs3testsuite=ON requires both -Dtesting=ON and -Dpyroot=ON)")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dpyroot=ON)
 endif()
 
 if(unfold AND NOT xml)
-  message(STATUS "Cannot enable unfold without enabling xml: unfold is disabled.")
-  set(unfold OFF)
+  message(SEND_ERROR "Cannot enable unfold without enabling -Dxml=ON.")
+  list(APPEND HOTFIX_BUILD_FLAGS -Dxml=ON)
 endif()
 
 if (NOT builtin_cling)
   if (builtin_clang OR builtin_llvm)
     message(WARNING "No need to build internal llvm or clang. Consider turning builtin_clang=Off and builtin_llvm=Off")
+    list(APPEND HOTFIX_BUILD_FLAGS -Dbuiltin_clang=OFF)
+    list(APPEND HOTFIX_BUILD_FLAGS -Dbuiltin_llvm=OFF)
   endif()
 endif(NOT builtin_cling)
 
 if(NOT http AND webgui)
-   message(WARNING "Cannot build WebGui components without HTTP: webgui is disabled.")
-   set(webgui OFF)
+   message(SEND_ERROR "Cannot build WebGui components without HTTP: enable -Dhttp=ON or set -Dwebgui=OFF.")
+   list(APPEND HOTFIX_BUILD_FLAGS -Dwebgui=OFF)
 endif()
 
 if(NOT webgui)
-   set(qt6web OFF CACHE BOOL "Disabled because webgui not build" FORCE)
-   set(cefweb OFF CACHE BOOL "Disabled because webgui not build" FORCE)
+    if(qt6web)
+        message(SEND_ERROR "Cannot build qt6web without webgui and http: enable -Dwebgui=ON -Dhttp=ON or set -Dqt6web=OFF.")
+        list(APPEND HOTFIX_BUILD_FLAGS -Dqt6web=OFF)
+    endif()
+    if(qt6web)
+        message(SEND_ERROR "Cannot build cefweb without webgui and http: enable -Dwebgui=ON -Dhttp=ON or set -Dcefweb=OFF.")
+        list(APPEND HOTFIX_BUILD_FLAGS -Dcefweb=OFF)
+    endif()
 endif()
 
 #---Removed options------------------------------------------------------------