Highly nested UNPACKed data causes panic
See attached source files. I get the following error:
[3 of 3] Compiling Data.BigWord ( src/Data/BigWord.hs, .stack-work/dist/x86_64-linux/Cabal-2.0.0.0/build/Data/BigWord.o )
ghc: panic! (the 'impossible' happened)
(GHC version 8.2.0.20170505 for x86_64-unknown-linux):
urk! lookup local fingerprint
D:R:DoubleWordDoubleWord2
[cESifd :-> (BigWord2, acd0b93ce6ccc191df910f3c0527af52),
cESife :-> (BigWord3, c2394bb5a6246cea8260b764c4645609),
cESiqK :-> (BigWord4, dfeb99d5c409e91fe7084935101bb1a8),
cESiqT :-> (R:DoubleWordDoubleWord3,
00000000000000000000000000000000),
cESiqV :-> (D:R:DoubleWordDoubleWord4,
00000000000000000000000000000000),
cESir1 :-> (D:R:BigWord4, 7d2736129b3a85c7e71bc1954bb41ec0),
dESiqK :-> (BigWord4, d51a0117843c625086a534a6e4b47d85),
iESiqK :-> (BigWord4, 139d5d98471af07fbafb30541b5ec225),
iESiqX :-> ($WBigWord4, df51c2cc8c85fdd30898a16f2568c91a)]
Call stack:
CallStack (from HasCallStack):
prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1134:58 in ghc:Outputable
callStackDoc, called at compiler/utils/Outputable.hs:1138:37 in ghc:Outputable
pprPanic, called at compiler/iface/MkIface.hs:508:37 in ghc:MkIface
I need to use ghc-8.2.1 because it seems to be the earliest version that contains the fixes in https://ghc.haskell.org/trac/ghc/ticket/3990, without which the UNPACKs will be ignored.
Trac metadata
Trac field | Value |
---|---|
Version | 8.2.1-rc2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | #3990 (closed) |
Blocking | |
CC | |
Operating system | |
Architecture |