Simon Jakobi pushed to branch wip/sjakobi/T27534 at Glasgow Haskell Compiler / GHC Commits: 688b520f by Simon Jakobi at 2026-07-22T13:21:21+02:00 testsuite: Make T17088 an effective reproducer Initialize each byte array so that the test does not depend on allocator contents. Run the test only with the compacting collector and restore the compiler and RTS settings that trigger #17088. Disable STG lambda lifting because it removes the closure shape needed to reproduce the original pointer-tagging failure. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 2 changed files: - testsuite/tests/rts/T17088.hs - testsuite/tests/rts/all.T Changes: ===================================== testsuite/tests/rts/T17088.hs ===================================== @@ -2,6 +2,9 @@ {-# LANGUAGE MagicHash #-} {-# LANGUAGE UnboxedTuples #-} +-- Lambda lifting removes the closure shape needed to reproduce #17088. +{-# OPTIONS_GHC -fno-stg-lift-lams #-} + module Main (main) where import Data.Word @@ -27,7 +30,9 @@ instance Show Bytes where bytesAllocRet :: Int -> IO Bytes bytesAllocRet (I# sz) = IO $ \s -> case newAlignedPinnedByteArray# sz 8# s of - (# s', mba #) -> (# s', Bytes mba #) + (# s', mba #) -> + case writeWord8Array# mba 0# (wordToWord8# 0##) s' of + s'' -> (# s'', Bytes mba #) ------------------------------------------------------------------------ ===================================== testsuite/tests/rts/all.T ===================================== @@ -540,8 +540,11 @@ test('RestartEventLogging', compile_and_run, ['RestartEventLogging_c.c']) test('T17088', - [extra_ways(['compacting_gc']), extra_run_opts('+RTS -A256k -RTS')], - compile_and_run, ['-rtsopts -O2']) + [ only_ways(['compacting_gc']) + , extra_ways(['compacting_gc']) + , extra_run_opts('+RTS -A128k -RTS') + ], + compile_and_run, ['-rtsopts -O1']) test('T15427', js_broken(22374), compile_and_run, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/688b520f88f6f739431d7ba173124db4... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/688b520f88f6f739431d7ba173124db4... You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help