diff --git a/docs/conf.py b/docs/conf.py

index d2e19c6..fb540a3 100644

--- a/docs/conf.py

+++ b/docs/conf.py

@@ -44,29 +44,6 @@ import subprocess

 _project_root = pathlib.Path(__file__).parent.parent

 _source_root = _project_root / "src"

-_git_reference = subprocess.run(

-    ["git", "rev-parse", "--abbrev-ref", "HEAD"],

-    text=True,

-    encoding="utf8",

-    capture_output=True,

-    check=True,

-).stdout

-

-

-# Try to find URL fragment for the GitHub source page based on current

-# branch or tag.

-

-if _git_reference == "HEAD":

-    # It looks like the branch has no name.

-    # Fallback to commit ID.

-    _git_reference = subprocess.getoutput("git rev-parse HEAD")

-

-if os.environ.get("READTHEDOCS", "") == "True":

-    rtd_version = os.environ.get("READTHEDOCS_VERSION", "")

-    if "." in rtd_version:

-        # It looks like we have a tag build.

-        _git_reference = rtd_version

-

 pydoctor_args = [

     # pydoctor should not fail the sphinx build, we have another tox environment for that.

     "--intersphinx=https://docs.twisted.org/en/twisted-22.1.0/api/objects.inv",

@@ -75,7 +52,6 @@ pydoctor_args = [

     "--intersphinx=https://zopeinterface.readthedocs.io/en/latest/objects.inv",

     # TODO: not sure why I have to specify these all twice.

     f"--config={_project_root}/.pydoctor.cfg",

-    f"--html-viewsource-base=https://github.com/glyph/automat/tree/{_git_reference}/src",

     f"--project-base-dir={_source_root}",

     "--html-output={outdir}/api",

     "--privacy=HIDDEN:automat.test.*",