--- a/setup.py	Mon Jun 14 21:46:10 2021 -0400
+++ b/setup.py	Sat Jun 19 14:22:36 2021 -0400
@@ -27,6 +27,8 @@
 
 from setuptools import setup
 
+from sysconfig import get_path
+
 import sys, os
 from glob import glob
 
@@ -49,6 +51,52 @@
     script = module.replace('_', '-')
     return '%s = roundup.scripts.%s:run' % (script, module)
 
+def make_data_files_absolute(data_files, prefix):
+    """Using setuptools data files are put under the egg install directory
+       if the datafiles are relative paths. We don't want this. Data files
+       like man pages, documentation, templates etc. should be installed
+       in a directory outside of the install directory. So we prefix
+       all datafiles making them absolute so man pages end up in places
+       like: /usr/local/share/man, docs in /usr/local/share/doc/roundup,
+       templates in /usr/local/share/roundup/templates.
+    """
+    new_data_files = [ (os.path.join(prefix,df[0]),df[1])
+                       for df in data_files ]
+
+    return new_data_files
+
+def get_prefix():
+    """Get site specific prefix using --prefix, platform lib or
+       sys.prefix.
+    """
+    prefix_arg=False
+    prefix=""
+    for a in sys.argv:
+        if prefix_arg:
+            prefix=a
+            break
+        # is there a short form -p or something for this??
+        if a.startswith('--prefix'):
+            if a == '--prefix':
+                # next argument is prefix
+                prefix_arg=True
+                continue
+            else:
+                # strip '--prefix='
+                prefix=a[9:]
+    if prefix:
+        return prefix
+    else:
+        # get the platform lib path.
+        plp = get_path('platlib')
+        # nuke suffix that matches lib/* and return prefix
+        head, tail = os.path.split(plp)
+        while tail != 'lib' and head != '':
+            head, tail = os.path.split(head)
+        if not head:
+            head = sys.prefix
+        return head
+
 
 def main():
     # template munching
@@ -93,6 +141,8 @@
     data_files.append(include('share/doc/roundup/html/_sources', '*'))
     data_files.append(include('share/doc/roundup/html/_static', '*'))
 
+    data_files = make_data_files_absolute(data_files, get_prefix())
+
     # perform the setup action
     from roundup import __version__