File doc-build-use-sphinx-build-3.patch of Package fmt-7.1.3

diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index 06848450..8e5e8a83 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -5,10 +5,11 @@ if (NOT DOXYGEN)
 endif ()
 
 find_package(PythonInterp QUIET REQUIRED)
+find_program(SPHINX_EXECUTABLE NAMES sphinx-build sphinx-build-3)
 
 add_custom_target(doc
   COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/build.py
-                               ${FMT_VERSION}
+                               ${SPHINX_EXECUTABLE} ${FMT_VERSION}
   SOURCES api.rst syntax.rst usage.rst build.py conf.py _templates/layout.html)
 
 include(GNUInstallDirs)
diff --git a/doc/build.py b/doc/build.py
index 59a7b498..8562d1bf 100755
--- a/doc/build.py
+++ b/doc/build.py
@@ -7,7 +7,7 @@ from subprocess import check_call, check_output, CalledProcessError, Popen, PIPE
 
 versions = ['1.0.0', '1.1.0', '2.0.0', '3.0.2', '4.0.0', '4.1.0', '5.0.0', '5.1.0', '5.2.0', '5.2.1', '5.3.0', '6.0.0', '6.1.0', '6.1.1', '6.1.2', '6.2.0', '6.2.1', '7.0.0', '7.0.1', '7.0.2', '7.0.3', '7.1.0', '7.1.1', '7.1.2', '7.1.3']
 
-def build_docs(version='dev', **kwargs):
+def build_docs(sphinx_executable='sphinx-build', version='dev', **kwargs):
   doc_dir = kwargs.get('doc_dir', os.path.dirname(os.path.realpath(__file__)))
   work_dir = kwargs.get('work_dir', '.')
   include_dir = kwargs.get(
@@ -50,7 +50,7 @@ def build_docs(version='dev', **kwargs):
     raise CalledProcessError(p.returncode, cmd)
   html_dir = os.path.join(work_dir, 'html')
   main_versions = reversed(versions[-3:])
-  check_call(['sphinx-build',
+  check_call([sphinx_executable,
               '-Dbreathe_projects.format=' + os.path.abspath(doxyxml_dir),
               '-Dversion=' + version, '-Drelease=' + version,
               '-Aversion=' + version, '-Aversions=' + ','.join(main_versions),
@@ -69,4 +69,4 @@ def build_docs(version='dev', **kwargs):
   return html_dir
 
 if __name__ == '__main__':
-  build_docs(sys.argv[1])
+  build_docs(sys.argv[1], sys.argv[2])
-- 
2.28.0