diff --git a/vinca/generate_gha.py b/vinca/generate_gha.py
index 4dc60c7..be243a6 100644
--- a/vinca/generate_gha.py
+++ b/vinca/generate_gha.py
@@ -192,6 +192,17 @@ def normalize_version(version: str) -> str:
     return version
 
 
+# pixi clones git dependencies (e.g. vinca) into its cache, which setup-pixi saves.
+# git's background auto-maintenance can leave a lock file in such a clone ("hardlink
+# different from source at .../commit-graph-chain.lock"), which then breaks every
+# later run restoring that cache. This step runs before Setup pixi, so it also covers
+# the build script.
+DISABLE_GIT_MAINTENANCE_STEP: dict[str, Any] = {
+    "name": "Disable git auto-maintenance",
+    "run": "git config --global maintenance.auto false && git config --global gc.auto 0",
+}
+
+
 def get_setup_pixi_step(
     setup_pixi_version: str = DEFAULT_SETUP_PIXI_VERSION,
     pixi_version: str = DEFAULT_PIXI_VERSION,
@@ -247,6 +258,7 @@ def build_unix_pipeline(
                     "name": "Checkout code",
                     "uses": "actions/checkout@v7",
                 },
+                DISABLE_GIT_MAINTENANCE_STEP,
                 get_setup_pixi_step(setup_pixi_version, pixi_version),
                 {
                     "name": f"Build {' '.join([pkg for pkg in batch])}",
@@ -371,6 +383,7 @@ def build_win_pipeline(
 
             steps = [
                 {"name": "Checkout code", "uses": "actions/checkout@v7"},
+                DISABLE_GIT_MAINTENANCE_STEP,
                 get_setup_pixi_step(setup_pixi_version, pixi_version),
                 {
                     "uses": "egor-tensin/cleanup-path@v5",
diff --git a/vinca/test_generate_gha.py b/vinca/test_generate_gha.py
index 4745084..08b1c0d 100644
--- a/vinca/test_generate_gha.py
+++ b/vinca/test_generate_gha.py
@@ -50,7 +50,10 @@ def test_unix_pipeline_sets_up_pixi(tmp_path):
     )
 
     workflow = pytest.importorskip("yaml").safe_load(outfile.read_text())
-    setup_step = workflow["jobs"]["stage_0_job_0"]["steps"][1]
+    steps = workflow["jobs"]["stage_0_job_0"]["steps"]
+    assert steps[1]["name"] == "Disable git auto-maintenance"
+    assert "maintenance.auto false" in steps[1]["run"]
+    setup_step = steps[2]
     assert setup_step == {
         "name": "Setup pixi",
         "uses": "prefix-dev/setup-pixi@v0",