From 89a5bea99834ccea3245ff1be1f5b5e29a195c96 Mon Sep 17 00:00:00 2001
From: Matthew Feickert <matthew.feickert@cern.ch>
Date: Mon, 1 Dec 2025 18:35:12 -0700
Subject: [PATCH] ci: Set BASE_URL required for MyST html build

* The 'x build --html' of myst and jupyter-book require the environmental
  variable 'BASE_URL' to be set.
   - c.f. https://mystmd.org/guide/deployment#deploy-base-url
   - c.f. https://mystmd.org/guide/deployment-github-pages#base-url-configuration-for-github-pages
---
 .github/workflows/deploy-jupyter-book.yml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/.github/workflows/deploy-jupyter-book.yml b/.github/workflows/deploy-jupyter-book.yml
index f210423..be6b0dd 100644
--- a/.github/workflows/deploy-jupyter-book.yml
+++ b/.github/workflows/deploy-jupyter-book.yml
@@ -22,6 +22,10 @@ jobs:
   build-book:
     runs-on: ubuntu-latest
 
+    env:
+      # Set BASE_URL required for build --html
+      BASE_URL: /${{ github.event.repository.name }}
+
     steps:
     - uses: actions/checkout@v6