Index: flang/docs/conf.py
--- flang/docs/conf.py.orig
+++ flang/docs/conf.py
@@ -22,12 +22,22 @@ from datetime import date
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
-    "myst_parser",
     "sphinx.ext.todo",
     "sphinx.ext.mathjax",
     "sphinx.ext.intersphinx",
     "sphinx.ext.autodoc",
 ]
+
+# When building man pages, we do not use the markdown pages,
+# So, we can continue without the myst_parser dependencies.
+# Doing so reduces dependencies of some packaged llvm distributions.
+try:
+    import myst_parser
+
+    extensions.append("myst_parser")
+except ImportError:
+    if not tags.has("builder-man"):
+        raise
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]