#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal
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Reporter: hvr | Owner: (none)
Type: bug | Status: new
Priority: high | Milestone: 8.4.1
Component: Compiler | Version: 8.3
Keywords: | Operating System: Unknown/Multiple
Architecture: | Type of failure: Compile-time
Unknown/Multiple | crash or panic
Test Case: | Blocked By:
Blocking: | Related Tickets: #14236
Differential Rev(s): | Wiki Page:
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When doing a default build of GHC HEAD (i.e. without `mk/build.mk`), GHC
panics:
{{{
$ make V=0
===--- building phase 0
make --no-print-directory -f ghc.mk phase=0 phase_0_builds
make[1]: Nothing to be done for 'phase_0_builds'.
===--- building phase 1
make --no-print-directory -f ghc.mk phase=1 phase_1_builds
make[1]: Nothing to be done for 'phase_1_builds'.
===--- building final phase
make --no-print-directory -f ghc.mk phase=final all
HC [stage 1] libraries/base/dist-install/build/Data/Typeable/Internal.o
ghc-stage1: panic! (the 'impossible' happened)
(GHC version 8.3.20170922 for x86_64-unknown-linux):
Template variable unbound in rewrite rule
Variable: cobox_a3S9
Rule "SC:mkTrApp0"
Rule bndrs: [k1_X4g7, b_X4gb, k1_a3RW, a_a3RX, k1_X426, b_X42a,
b_a3RY, sc_s7Yv, sc_s7Yr, sc_s7Ys, sc_s7Yt, cobox_a3S9,
cobox_a3RZ,
cobox_X42x, cobox_a3S8]
LHS args: [TYPE: TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)),
TYPE: TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *, TYPE:
(->),
TYPE: (b_X4gb |> Sym (cobox_a3S9 (Coh (Sym (Coh