From: James Addison <jay@jp-hosting.net>
Date: Sat, 29 Mar 2025 20:32:21 +0000
Subject: enable a fixed salt for matplotlib hash-based ID-generation of SVG paths
 .
 This removes a source of per-build variance due by avoiding the (default)
 use of randomized UUID4-based salt values.
Bug-Debian: http://bugs.debian.org/1064858
diff --git a/docs/conf.py b/docs/conf.py
index 7a9c7d7..badebc3 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -49,6 +49,9 @@ exclude_patterns.append('_templates')  #
 exclude_patterns.append('psf_spec/*')  # noqa
 
 plot_formats = ['png', 'hires.png', 'pdf', 'svg']
+plot_rcparams = {
+    'svg.hashsalt': 'https://reproducible-builds.org',
+}
 
 # This is added to the end of RST files - a good place to put
 # substitutions to be used globally.