Address doc generation not finding git repo in CI

.github/workflows/cd.yml

@@ -144,7 +144,7 @@ jobs:
           apt-get update
           apt-get install -q -y --no-install-recommends python3-pip doxygen
           apt-get install -q -y --no-install-recommends latexmk texlive-latex-extra tex-gyre texlive-fonts-recommended texlive-latex-recommended
-          pip3 install exhale sphinx-sitemap sphinx-design gitpython
+          pip3 install exhale sphinx-sitemap sphinx-design
           pip3 install sphinxawesome-theme --pre
           pip3 install "sphinx<7,>6"
 

.github/workflows/ci.yml

@@ -150,7 +150,7 @@ jobs:
           apt-get update
           apt-get install -q -y --no-install-recommends python3-pip doxygen
           apt-get install -q -y --no-install-recommends latexmk texlive-latex-extra tex-gyre texlive-fonts-recommended texlive-latex-recommended
-          pip3 install exhale sphinx-sitemap sphinx-design gitpython
+          pip3 install exhale sphinx-sitemap sphinx-design
           pip3 install sphinxawesome-theme --pre
           pip3 install "sphinx<7,>6"
 

docs/conf.py

@@ -1,9 +1,9 @@
+import os
 from sys import argv
 from dataclasses import asdict
 from sphinxawesome_theme import ThemeOptions
 from sphinxawesome_theme.postprocess import Icons
 import lxml.etree
-import git
 
 # Project information
 project = 'wavemap'
@@ -127,8 +127,13 @@
 highlight_language = 'cpp'
 
 # Provide a short syntax to link to files in the repository
-repo = git.Repo(search_parent_directories=True)
-sha = repo.head.object.hexsha
+sha = os.environ.get('GITHUB_SHA')  # Attempt to read it from CI env variables
+if sha is None:
+    import git
+
+    repo = git.Repo(os.path.dirname(__file__), search_parent_directories=True)
+    sha = repo.head.object.hexsha
+
 extlinks = {
     "gh_file": (f"https://github.com/ethz-asl/wavemap/tree/{sha}/%s", "%s"),
 }