srs = SRS.new(secret='secret')
srs.forward('foo@example.org', 'srs.example.com')
[..]
  File "/usr/lib/python3/dist-packages/SRS/Base.py", line 250, in hash_create
    hash = base64.encodestring(h.digest())
AttributeError: module 'base64' has no attribute 'encodestring'

However, issue seems to be fixed upstream:
https://github.com/sdgathman/pysrs/blob/master/SRS/Base.py#L250

We believe that the bug you reported is fixed in the latest version of
pysrs, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 994192@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Sandro Knauß <hefee@debian.org> (supplier of updated pysrs package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Tue, 21 Jun 2022 02:14:51 +0200
Source: pysrs
Architecture: source
Version: 1.0.4-1
Distribution: unstable
Urgency: medium
Maintainer: Debian Python Team <team+python@tracker.debian.org>
Changed-By: Sandro Knauß <hefee@debian.org>
Closes: 994192 1008829
Changes:
 pysrs (1.0.4-1) unstable; urgency=medium
 .
   * New upstream release (Closes: #1008829, #994192)
   * Set Rules-Requires-Root to no.
   * Set section:utils for pysrs-bin.
   * Add autopkgtests.
   * Add python3-milter to Suggests.
   * Remove upstream applied patch.
   * Update install files.
   * Add python3-setuptools to Build-Depends.
   * Update Standards-Version (no changes needed).
   * Update copyright info for debian files.
   * Replace link to github repo for source.
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