GHC fails with “StgCmmEnv: variable not found” when trying to compile order-maintenance-0.2.1.0

When trying to build order-maintenance-0.2.1.0, GHC 8.4.2-rc1 panics. Its output is as follows:

[ 1 of 21] Compiling Data.Order.Algorithm.Raw ( src/library/Data/Order/Algorithm/Raw.hs, /home/wolfgang/Entwicklung/Haskell/order-maintenance-0.2.1.0/dist-newstyle/build/x86_64-linux/ghc-8.4.1.20180329/order-maintenance-0.2.1.0/build/Data/Order/Algorithm/Raw.o )
[ 2 of 21] Compiling Data.Order.Algorithm.Raw.DietzSleatorAmortizedLog ( src/library/Data/Order/Algorithm/Raw/DietzSleatorAmortizedLog.hs, /home/wolfgang/Entwicklung/Haskell/order-maintenance-0.2.1.0/dist-newstyle/build/x86_64-linux/ghc-8.4.1.20180329/order-maintenance-0.2.1.0/build/Data/Order/Algorithm/Raw/DietzSleatorAmortizedLog.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 8.4.1.20180329 for x86_64-unknown-linux):
	StgCmmEnv: variable not found
  x_a46z
  local binds for:
  $tc'Label
  $tcLabel
  $tc'Cell
  $tcCell
  $trModule
  $tc'Cell1
  $tc'Cell2
  $tc'Cell3
  $trModule1
  $trModule2
  $trModule3
  $trModule4
  $tc'Label1
  $tc'Label2
  $tc'Label3
  $tcCell1
  $tcCell2
  $tcLabel1
  $tcLabel2
  lvl_r4UD
  lvl1_r4UE
  lvl2_r4UF
  lvl3_r4UG
  lvl4_r4UH
  lvl5_r4UI
  lvl6_r4UJ
  lvl7_r4UK
  lvl8_r4UL
  lvl9_r4UM
  lvl10_r4UN
  lvl11_r4UO
  lvl12_r4UP
  lvl13_r4UQ
  lvl14_r4UR
  lvl15_r4US
  lvl16_r4UT
  lvl17_r4UU
  $krep_r4UV
  $krep1_r4UW
  $krep2_r4UX
  lvl18_r4UY
  $krep3_r4UZ
  $krep4_r4V0
  $krep5_r4V1
  $krep6_r4V2
  $krep7_r4V3
  $krep8_r4V4
  $krep9_r4V5
  lvl19_r4V6
  lvl20_r4V7
  lvl21_r4V8
  lvl22_r4V9
  lvl23_r4Va
  lvl24_r4Vb
  lvl25_r4Vc
  ww_s4W2
  lwild_s4W3
  lwild1_s4W4
  noOfLabels_s4W5
  noOfLabels1_s4W6
  labelMask_s4W7
  $wnewAfterCell_s4Wa
  ww1_s4Wb
  ipv1_s4Wf
  wild_s4Wg
  ds_s4Wh
  ds2_s4Wi
  ww2_s4Wk
  ww3_s4Wl
  ww4_s4Wn
  ww5_s4Wo
  wild1_s4Wq
  smallGap_s4Wr
  wild2_s4Ws
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable
        pprPanic, called at compiler/codeGen/StgCmmEnv.hs:149:9 in ghc:StgCmmEnv

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

The same problem exists with GHC 8.4.1.

Trac metadata

Trac field	Value
Version	8.4.2-rc1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture