[GHC] #14802: panic! (the 'impossible' happened)
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Keywords: | Operating System: Linux Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I was debugging and tried to print a matrix but got the following error message: <interactive>:34:21: error:<interactive>: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): No skolem info: a1_IhXR[rt] Has this been fixed in the newer version of ghc? If so, what's the fastest way to update? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => infoneeded Comment: It's hard to say without some more context. Can you post a minimal example of how to reproduce this panic? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by Ebanflo): * Attachment "ghciBug.hs" added. Attempted replication of the situation that caused the error. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by Ebanflo): * Attachment "ghciBug.2.hs" added. Attempted replication of what caused the error. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by Ebanflo: Old description:
I was debugging and tried to print a matrix but got the following error message:
<interactive>:34:21: error:<interactive>: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): No skolem info: a1_IhXR[rt]
Has this been fixed in the newer version of ghc? If so, what's the fastest way to update?
New description: I was debugging and tried to print a matrix but got the following error message: <interactive>:34:21: error:<interactive>: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): No skolem info: a1_IhXR[rt] UPDATE: I downloaded ghc 8.2.2, extracted, ran `./config` and then `make install`. Now when I run `ghc -v` it says Glasgow Haskell Compiler, Version 8.2.2, stage 2 booted by GHC version 8.0.2 But when I run `ghci` it says that it is version 8.0.2 and it gives the same 'impossible' error as I did before. I put the function I was debugging in a small file with the other functions that it depends on (sorry, I accidentally attached the same file twice). It would be very difficult to replicate the test cases I was working with without copying a lot more code. I tried running the function on a simple test case (some 3x4 matrix) and when I tried to print the helper variable desired (mat1) it said that the runtime type of mat1 could not be determined. This was fixed by giving the function `calc` a type signature. Indeed, when I put this type signature in my actual code, I was able to debug it without a problem. My biggest concern at this point is how to boot ghci 8.2.2 instead of 8.0.2, and because of this I'm not sure whether or not what I've described here is a problem with 8.2.2 or just 8.0.2. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by hsyl20): You can use `stack` to easily launch a GHCi session for different GHC compiler versions: {{{ stack --resolver=ghc-8.0.1 repl --package vector --package primitive stack --resolver=ghc-8.0.2 repl --package vector --package primitive stack --resolver=ghc-8.2.2 repl --package vector --package primitive }}} Otherwise use `which ghci` to check which `ghci` is being used or use `ghc --interactive` instead of `ghci` (as `ghc -v` shows the expected version, it should work). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14802: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: Ebanflo | Owner: (none) Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Debugging) | Resolution: | Keywords: Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Thanks for posting the code, Ebanflo. But I'm still missing some important info here—I load the file into `ghci-8.0.2`, but I don't experience any sort of panic. What am I doing wrong? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14802#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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