setup: doc string describing what the require_auto_deps() function is for

diff --git a/_auto_deps.py b/_auto_deps.py
index ee3a3eb5b12750d12715d42df6f3aefb2a9fc6e0..0712ec0262810fcc6c23f6ed29454234e475312d 100644 (file)
--- a/_auto_deps.py
+++ b/_auto_deps.py
@@ -20,6 +20,13 @@ if hasattr(sys, 'frozen'):
     install_requires=[]
 
 def require_auto_deps():
+    """
+    The purpose of this function is to raise a pkg_resources exception if any of the
+    requirements can't be imported.  This is just to give earlier and more explicit error
+    messages, as opposed to waiting until the source code tries to import some module from one
+    of these packages and gets an ImportError.  This function gets called from
+    src/allmydata/__init__.py .
+    """
     import pkg_resources
     for requirement in install_requires:
         try: