--- CMakeLists.txt.orig	2023-12-23 01:33:41
+++ CMakeLists.txt	2023-12-29 23:44:53
@@ -373,34 +373,41 @@
 endif() # JPEGXL_ENABLE_DOXYGEN
 
 if(JPEGXL_ENABLE_MANPAGES)
-  find_program(ASCIIDOC a2x)
   if(ASCIIDOC)
-    file(STRINGS "${ASCIIDOC}" ASCIIDOC_SHEBANG LIMIT_COUNT 1)
-    if(ASCIIDOC_SHEBANG MATCHES "sh$" OR MINGW)
-      set(ASCIIDOC_PY_FOUND ON)
-      # Run the program directly and set ASCIIDOC as empty.
-      set(ASCIIDOC_PY "${ASCIIDOC}")
-      set(ASCIIDOC "")
-    elseif(ASCIIDOC_SHEBANG MATCHES "python2")
-      find_package(Python2 COMPONENTS Interpreter)
-      set(ASCIIDOC_PY_FOUND "${Python2_Interpreter_FOUND}")
-      set(ASCIIDOC_PY Python2::Interpreter)
-    elseif(ASCIIDOC_SHEBANG MATCHES "python3")
-      find_package(Python3 COMPONENTS Interpreter)
-      set(ASCIIDOC_PY_FOUND "${Python3_Interpreter_FOUND}")
-      set(ASCIIDOC_PY Python3::Interpreter)
-    else()
-      find_package(Python COMPONENTS Interpreter QUIET)
-      if(NOT Python_Interpreter_FOUND)
-        find_program(ASCIIDOC_PY python)
-        if(ASCIIDOC_PY)
-          set(ASCIIDOC_PY_FOUND ON)
-        endif()
+    set(ASCIIDOC_PY_FOUND ON)
+    set(ASCIIDOC_PY "${ASCIIDOC}")
+    set(ASCIIDOC "")
+  else()
+    find_program(ASCIIDOC a2x)
+    if(ASCIIDOC)
+      file(STRINGS "${ASCIIDOC}" ASCIIDOC_SHEBANG LIMIT_COUNT 1)
+      if(ASCIIDOC_SHEBANG MATCHES "/sh|/bash" OR MINGW)
+        set(ASCIIDOC_PY_FOUND ON)
+        # Run the program directly and set ASCIIDOC as empty.
+        set(ASCIIDOC_PY "${ASCIIDOC}")
+        set(ASCIIDOC "")
+      elseif(ASCIIDOC_SHEBANG MATCHES "python2")
+        find_package(Python2 COMPONENTS Interpreter)
+        set(ASCIIDOC_PY_FOUND "${Python2_Interpreter_FOUND}")
+        set(ASCIIDOC_PY Python2::Interpreter)
+      elseif(ASCIIDOC_SHEBANG MATCHES "python3")
+        find_package(Python3 COMPONENTS Interpreter)
+        set(ASCIIDOC_PY_FOUND "${Python3_Interpreter_FOUND}")
+        set(ASCIIDOC_PY Python3::Interpreter)
       else()
-        set(ASCIIDOC_PY_FOUND "${Python_Interpreter_FOUND}")
-        set(ASCIIDOC_PY Python::Interpreter)
-      endif()
-    endif()
+         find_package(Python COMPONENTS Interpreter QUIET)
+         if(NOT Python_Interpreter_FOUND)
+           find_program(ASCIIDOC_PY python)
+           if(ASCIIDOC_PY)
+             set(ASCIIDOC_PY_FOUND ON)
+           endif()
+         else()
+            set(ASCIIDOC_PY_FOUND "${Python_Interpreter_FOUND}")
+            set(ASCIIDOC_PY Python::Interpreter)
+         endif()
+      endif() # ASCIIDOC_SHEBANG
+    endif() # ASCIIDOC
+  endif() # ASCIIDOC
 
     if (ASCIIDOC_PY_FOUND)
       set(MANPAGE_FILES "")
@@ -422,9 +429,6 @@
       add_custom_target(manpages ALL DEPENDS ${MANPAGES})
       install(FILES ${MANPAGE_FILES} DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
     endif()  # ASCIIDOC_PY_FOUND
-  else()
-    message(WARNING "asciidoc was not found, the man pages will not be installed.")
-  endif()  # ASCIIDOC
 endif()  # JPEGXL_ENABLE_MANPAGES
 
 # Example usage code.