Increase requirements for breathe.

diff --git a/docs/requirements.txt b/docs/requirements.txt
index 4466c18..e50fec2 100644 (file)
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,4 @@
-breathe
+breathe>=4.26
 sphinx>=3.4.3,<4.0
 sphinx_rtd_theme
 # sphinx_tabs v1.2.1 is required for Sphinx 2