Fix exception causes all over the codebase

1 files changed, 2 insertions, 2 deletions

diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index 5340c93f9..99d7aa13b 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -140,7 +140,7 @@ class BuildInfo:
             build_info.tags_hash = lines[3].split()[1].strip()
             return build_info
         except Exception as exc:
-            raise ValueError(__('build info file is broken: %r') % exc)
+            raise ValueError(__('build info file is broken: %r') % exc) from exc
 
     def __init__(self, config: Config = None, tags: Tags = None, config_categories: List[str] = []) -> None:  # NOQA
         self.config_hash = ''
@@ -1015,7 +1015,7 @@ class StandaloneHTMLBuilder(Builder):
             return
         except Exception as exc:
             raise ThemeError(__("An error happened in rendering the page %s.\nReason: %r") %
-                             (pagename, exc))
+                             (pagename, exc)) from exc
 
         if not outfilename:
             outfilename = self.get_outfilename(pagename)