Interesting. It works fine with Python 3.6 and latest master but segfaults in python 3.7.0 . I will try the latest python 3.7 branch later.

# Python 3.6 on Mac

(bpo34241-env)    mysite git:(master)   python
Python 3.6.4 (default, Mar 12 2018, 13:42:53)
[GCC 4.2.1 Compatible Apple LLVM 7.0.2 (clang-700.1.81)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>

# Changes made

diff --git a/mysite/templates/rest_framework/login_base.html b/mysite/templates/rest_framework/login_base.html
index aa91aae..48127ae 100644
--- a/mysite/templates/rest_framework/login_base.html
+++ b/mysite/templates/rest_framework/login_base.html
@@ -68,7 +68,7 @@
       <div class="well" style="width: 320px; margin-left: auto; margin-right: auto">
         <div class="row-fluid">
           <div>
-            <p><a href="{% url 'cas_ng_login' %}?next=/">{% trans "Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuks." %}</a></p>
+            <p><a href="{% url 'cas_ng_login' %}?next=/">{% trans "Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuksi." %}</a></p>
           </div>
         </div><!-- /row fluid -->
       </div><!--/.well-->

# Rendered content

      <div class="well" style="width: 320px; margin-left: auto; margin-right: auto">
        <div class="row-fluid">
          <div>
            <p><a href="/accounts/login?next=/">Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuksi.</a></p>
          </div>
        </div><!-- /row fluid -->
      </div><!--/.well-->

# python 3.8

Python 3.8.0a0 (heads/master:defcffd, Jul 27 2018, 04:59:27)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

# diff

diff --git a/mysite/templates/rest_framework/login_base.html b/mysite/templates/rest_framework/login_base.html
index aa91aae..48127ae 100644
--- a/mysite/templates/rest_framework/login_base.html
+++ b/mysite/templates/rest_framework/login_base.html
@@ -68,7 +68,7 @@
       <div class="well" style="width: 320px; margin-left: auto; margin-right: auto">
         <div class="row-fluid">
           <div>
-            <p><a href="{% url 'cas_ng_login' %}?next=/">{% trans "Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuks." %}</a></p>
+            <p><a href="{% url 'cas_ng_login' %}?next=/">{% trans "Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuksi." %}</a></p>
           </div>
         </div><!-- /row fluid -->
       </div><!--/.well-->

      </div><!--/.well-->

# Content rendered

      <div class="well" style="width: 320px; margin-left: auto; margin-right: auto">
        <div class="row-fluid">
          <div>
            <p><a href="/accounts/login?next=/">Kirjaudu sis‰‰n k‰ytt‰en Opintopolun tunnuksi.</a></p>
          </div>
        </div><!-- /row fluid -->
      </div><!--/.well-->

    </div><!-- /.row-fluid -->
  </div><!-- /.container-fluid -->

# Python 3.7

Python 3.7.0 (default, Jun 28 2018, 02:32:19)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

# segfaults

(bpo34241-37-venv) karthi@ubuntu-s-1vcpu-1gb-blr1-01:~/django-cas-crash/mysite$ python manage.py runserver 0.0.0.0:8000
Performing system checks...

System check identified no issues (0 silenced).
July 27, 2018 - 05:34:36
Django version 2.0.7, using settings 'mysite.settings'
Starting development server at http://0.0.0.0:8000/
Quit the server with CONTROL-C.
Segmentation fault (core dumped)



Thanks