Ben Gamari pushed to branch wip/T27456 at Glasgow Haskell Compiler / GHC Commits: 42860214 by Ben Gamari at 2026-06-29T11:12:36-04:00 base: Display ExceptionContext in WhileHandling's textual description As originally-implemented the implementation for `WhileHandling(displayExceptionAnnotation)` would display the `ExceptionContext` of the exception which it carries (as this was the behavior of `displayException`, in terms of which `displayExceptionAnnotation` was implemented). However, in 284ffab3 the definition of `SomeException(displayException)` was changed to exclude the `ExceptionContext`. This means that `WhileHandling(displayExceptionAnnotation)` fails to describe the provenance of the exception which it captures, greatly limiting its utility. Return the implementation to its originally-specified behavior by implementing `WhileHandling(displayExceptionAnnotation)` in terms of `displayExceptionWithInfo`. Fixes #27456. - - - - - 2 changed files: - + changelog.d/T27456 - libraries/ghc-internal/src/GHC/Internal/Exception/Type.hs Changes: ===================================== changelog.d/T27456 ===================================== @@ -0,0 +1,8 @@ +section: base +issues: #27456 +mrs: ! +synopsis: + Show `ExceptionContext` in `displayExceptionAnnotation` implementation of `WhileHandling` +description: + In the past ``displayException`` (in terms of which ``WhileHandling``\'s ``displayExceptionAnnotation` is implemented) was changed to hide ``ExceptionContext``. This regressed the behavior of ``displayExceptionAnnotation`` from that which was originally specified. Restore the intended behavior of showing the ``ExceptionContext`` of the carried exception. + ===================================== libraries/ghc-internal/src/GHC/Internal/Exception/Type.hs ===================================== @@ -84,7 +84,7 @@ data WhileHandling = WhileHandling SomeException deriving Show instance ExceptionAnnotation WhileHandling where displayExceptionAnnotation (WhileHandling e) = - "While handling " ++ case lines $ displayException e of + "While handling " ++ case lines $ displayExceptionWithInfo e of [] -> "" (l1:ls) -> -- Indent lines forward. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/42860214051bff4d0b8b4da4a722c3f7... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/42860214051bff4d0b8b4da4a722c3f7... You're receiving this email because of your account on gitlab.haskell.org.