diff --git a/aiida-registry-app/src/Components/Details.jsx b/aiida-registry-app/src/Components/Details.jsx
index 51918ff7..a1db0420 100644
--- a/aiida-registry-app/src/Components/Details.jsx
+++ b/aiida-registry-app/src/Components/Details.jsx
@@ -76,13 +76,24 @@ function Details({pluginKey}) {
       </div>
 
       <h3>Registry checks</h3>
-      {value.warnings ? (
+      {value.warnings || value.errors ? (
         <>
-        {value.warnings.map((warning) => (
-          <Alert severity="warning">{warning}</Alert>
-        ))}
+          {value.warnings && (
+            <>
+            {value.warnings.map((warning) => (
+              <Alert severity="warning">{warning}</Alert>
+            ))}
+            </>
+          )}
+          {value.errors && (
+            <>
+          {value.errors.map((error) => (
+            <Alert severity="error"><pre>{error}</pre></Alert>
+          ))}
+            </>
+          )}
         </>
-      ):(
+      ) : (
         <Alert severity="success">All checks passed!</Alert>
       )}
 
diff --git a/aiida_registry/fetch_metadata.py b/aiida_registry/fetch_metadata.py
index ff078cee..ab89aa2a 100644
--- a/aiida_registry/fetch_metadata.py
+++ b/aiida_registry/fetch_metadata.py
@@ -32,7 +32,10 @@
 from .parse_pypi import PypiData, get_pypi_metadata
 from .utils import fetch_file
 
-GITHUB_TOKEN = os.environ["GITHUB_TOKEN"]
+try:
+    GITHUB_TOKEN = os.environ["GITHUB_TOKEN"]
+except KeyError:
+    GITHUB_TOKEN = ""
 
 
 @lru_cache(maxsize=None)
@@ -354,12 +357,16 @@ def is_pip_url_pypi(string: str) -> bool:
     return PYPI_NAME_RE.match(string) is not None
 
 
-def add_warnings(metadata):
-    """Add fetch warnings to the data object."""
+def add_registry_checks(metadata, include_errors=False):
+    """Add fetch warnings/errors to the data object."""
     plugins_warnings = REPORTER.plugins_warnings
 
-    for name, warnings in plugins_warnings.items():
-        metadata[name]["warnings"] = warnings
+    if include_errors:
+        for name, error_list in plugins_warnings.items():
+            metadata["plugins"][name]["errors"] = error_list
+    else:
+        for name, warning_list in plugins_warnings.items():
+            metadata[name]["warnings"] = warning_list
 
     return metadata
 
@@ -379,9 +386,7 @@ def fetch_metadata(filter_list=None, fetch_pypi=True, fetch_pypi_wheel=True):
         plugins_metadata[plugin_name] = complete_plugin_data(
             plugin_data, fetch_pypi=fetch_pypi, fetch_pypi_wheel=fetch_pypi_wheel
         )
-
-    plugins_metadata = add_warnings(plugins_metadata)
-
+    plugins_metadata = add_registry_checks(plugins_metadata)
     REPORTER.info(f"{PLUGINS_METADATA} dumped")
 
     if os.environ.get("GITHUB_ACTIONS") == "true":
diff --git a/aiida_registry/test_install.py b/aiida_registry/test_install.py
index ceee37f7..fcb11d5b 100644
--- a/aiida_registry/test_install.py
+++ b/aiida_registry/test_install.py
@@ -10,7 +10,9 @@
 import sys
 from dataclasses import asdict, dataclass
 
-from . import PLUGINS_METADATA
+from aiida_registry.fetch_metadata import add_registry_checks
+
+from . import PLUGINS_METADATA, REPORTER
 
 # Where to mount the workdir inside the Docker container
 _DOCKER_WORKDIR = "/tmp/scripts"
@@ -72,6 +74,7 @@ def handle_error(process_result, message):
 
     if process_result.exit_code != 0:
         error_message = process_result.output.decode("utf8")
+        REPORTER.warn(f"{message}\n{error_message}")
         raise ValueError(f"{message}\n{error_message}")
 
     return error_message
@@ -87,6 +90,7 @@ def test_install_one_docker(container_image, plugin):
     is_package_importable = False
     process_metadata = {}
     error_message = ""
+    REPORTER.set_plugin_name(plugin["name"])
 
     print("   - Starting container for {}".format(plugin["name"]))
     container = client.containers.run(
@@ -219,6 +223,8 @@ def test_install_all(container_image):
             except KeyError:
                 continue
 
+    data = add_registry_checks(data, include_errors=True)
+
     print("Dumping plugins.json")
     with open(PLUGINS_METADATA, "w", encoding="utf8") as handle:
         json.dump(data, handle, indent=2)