GHC plans for 8.8.1

This page is our road-map for what will be in 8.8.

If you believe your favorite thing belongs in this list, but isn't there, please yell. If it's not in the road map, it probably won't get done. Without a lot of support, many things in the road map won't get done either, so we need your help!


  • 18 November 2018: Cut release branch
  • 25 November 2018: Release alpha1
  • 16 December 2018: Release alpha2
  • 6 January 2019: Release alpha3
  • 27 January 2019: Release alpha4
  • 17 February 2019: Release beta1
  • 15 March 2019: Final release

Libraries Status

See Libraries? and Migration/8.8.

Release highlights (planned)

Below are the major highlights of 8.8.


Build system and miscellaneous changes

Landed in master branch

Library changes

Build system and miscellaneous changes

Tickets marked merge with no milestone

Ticket Type Summary Priority Owner
No tickets found

Tickets slated for 8.8.1


Status: merge (22 matches)

Ticket Type Summary Priority Differential Rev(s) Owner
#16141 bug StrictData and TypeFamilies regression highest
#16188 bug GHC HEAD-only panic (buildKindCoercion) highest goldfire
#16204 bug GHC HEAD-only Core Lint error (Argument value doesn't match argument type) highest
#16225 bug GHC HEAD-only Core Lint error (Trans coercion mis-match) highest
#16331 bug REGRESSION: --supported-languages lies about supported languages, again highest
#16195 bug Program with trivial polymorphism leads to out of scope dictionary high
#8657 bug -fregs-graph still has a limit on spill slots normal archblob
#14729 bug normaliseType is not well-kinded normal
#15549 bug Core Lint error with EmptyCase normal
#15733 task Several links in GHC.Exts.Heap documentation are broken normal D5257
#15849 bug Error message: "Perhaps you need a let in a do block", when there is no do block. normal nineonine
#15897 bug Negative MUT time in +RTS -s -RTS when heap profiling is enabled normal
#16183 bug GHC HEAD regression: -ddump-splices incorrectly parenthesizes HsKindSig applications normal
#16230 bug API Annotations: more explicit foralls fixup normal alanz
#16236 bug API Annotations: AnnAt disconnected for TYPEAPP normal alanz
#16255 bug Visible kind application defeats type family with higher-rank result kind normal
#16265 bug API Annotations: parens anns discarded for `(*)` operator normal alanz
#16279 bug Lexer: Alternate Layout Rule injects actual not virtual braces normal alanz
#16287 bug :kind accepts bogus type normal
#16303 bug checkStack sanity check fails normal
#16311 task Suggest -XExistentialQuantification for 'forall' in data declarations normal
#16339 bug Cannot put (.) or (!) type operators into an export list normal

Status: patch (7 matches)

Ticket Type Summary Priority Differential Rev(s) Owner
#16022 bug Hadrian appears to link against libffi unconditionally highest Phab:D5427
#16201 bug ghci063 failing on Darwin highest
#16378 bug bkpcabal01 fails with recent Cabal highest
#11126 bug Entered absent arg in a Repa program high Phab:D3221 bgamari
#10069 bug CPR related performance issue normal !401
#15656 task Extend -Wall with incomplete-uni-patterns and incomplete-record-updates normal Phab:D5415 ckoparkar
#15896 task GHC API: add function to allow looking up Name for Located RdrName normal Phab:D5330 alanz

Status: upstream (5 matches)

Ticket Type Summary Priority Differential Rev(s) Owner
#13897 task Ship check-ppr in bindist and compile during testsuite run high Phab:D4039 alanz
#9775 bug "Failed to remove" errors during Windows build from hsc2hs normal
#10822 bug GHC inconsistently handles \\?\ for long paths on Windows normal Phab:D4416
#12965 bug String merging broken on Windows normal Phab:D3384
#15074 bug Possible uninitialised values in ffi64.c normal


Status: new (31 matches)

Ticket Type Summary Priority Owner
#14375 bug Implement with# primop highest bgamari
#15064 bug T8089 mysteriously fails when GHC is built with LLVM highest osa1
#15779 task Follow-ups to D5169 highest
#15919 task Deprecate split objects highest
#15948 bug Hadrian build fails on Windows when invoked without --configure flag highest
#16051 bug Cross compilation broken under Hadrian highest alpmestan
#16058 bug GHC built on macOS Mojave nondeterministically segfaults highest
#16398 bug Missing documentation in Windows bindist tarball highest
#8095 bug TypeFamilies painfully slow high goldfire
#8949 bug switch -msse2 to be on by default high
#12758 task Bring sanity to our performance testsuite high
#13253 bug Exponential compilation time with RWST & ReaderT stack with `-02` high bgamari, osa1
#13786 bug GHCi linker is dependent upon object file order high
#14069 bug RTS linker maps code as writable high rockbmb
#14974 bug 2-fold memory usage regression GHC 8.2.2 -> GHC 8.4.1 compiling `mmark` package high davide
#15059 bug ghcpkg05 fails high
#15262 bug GHC and iserv cannot agree on what an Integer is; insanity ensues high
#15383 bug T3171 doesn't terminate with Interrupted message on Darwin high
#15442 bug GhcStage3HcOpts passed to ghc-stage1 high
#15503 bug interpreter: sequence_ (replicate 100000000 (return ())) gobbles up memory high osa1
#15577 bug TypeApplications-related infinite loop (GHC 8.6+ only) high
#15703 bug Significant compilation time blowup when refactoring singletons-heavy code high
#15913 bug ghc-8.6.2 fails to build on s390x (unregisterised): ‘stg_MUT_ARR_PTRS_FROZEN0_info’ undeclared (first use in this function); did you mean ‘stg_MUT_ARR_PTRS_FROZEN_DIRTY_info’? high
#15971 bug Hadrian fails Shake's linter on Windows high
#15982 bug Hadrian's `--configure` flag is broken on Windows high
#16037 bug memcpy test inexplicably failing high
#16073 bug Hadrian build fails on Windows high
#16085 bug ffi018_ghci fails when unregisterised high
#15990 bug Dynamically built GHC crashes on MacOS normal
#16165 task Move Hadrian (github) wiki information to in-tree docs normal
#16217 task check-api-annotations should check that an annotation does not precede its span normal


Ticket Type Summary Priority Owner
No tickets found

Last modified 5 months ago Last modified on Dec 28, 2018 5:52:49 AM