fix: handle JSONDecodeError in fatbuildrctl

Properly handle and report JSON decode error in fatbuildrctl in case of
unexpected failure in fatbuildrweb.

fix #146

CHANGELOG.md

@@ -222,6 +222,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   syntax error during RPM packages builds (#170).
 - Fix crash of `fatbuildrctl` on missing source definition in YAML artifact
   definition file (#171).
+- Handle JSON decode error in `fatbuildrctl` in case of unexpected failure in
+  `fatbuildrweb` (#146).
 - docs:
   - Add missing path parameter in REST API to retrieve artifact information.
   - Add missing optional `architectures` parameter in instances pipelines

fatbuildr/protocols/http/client.py

@@ -19,6 +19,15 @@
 
 import requests
 
+# External requests library can use simplejson when available, with fallback to
+# standard json library. This module may receive JSONDecodeError from this
+# package, or from the standard library. Adopt the same import logic to catch
+# the correct error.
+try:
+    from simplejson import JSONDecodeError
+except ImportError:
+    from json import JSONDecodeError
+
 from . import JsonInstance, JsonRunnableTask, JsonArtifact
 from ..client import AbstractClient
 from ...errors import FatbuildrServerError, FatbuildrServerPermissionError
@@ -40,6 +49,10 @@ def error_handler_wrapper(*args, **kwargs):
             raise FatbuildrServerError(
                 f"unable to connect to {args[0].uri}: {err}"
             )
+        except JSONDecodeError as err:
+            raise FatbuildrServerError(
+                f"unable to decode JSON response to {args[0].uri}: {err}"
+            )
 
     return error_handler_wrapper