#8316: GHCi debugger segfaults when trying force a certain variable -------------------------------------+------------------------------------- Reporter: guest | Owner: Nolan Type: bug | Status: new Priority: high | Milestone: Component: GHCi | Version: 7.6.3 Resolution: | Keywords: debugger Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHCi crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by Nolan): * owner: (none) => Nolan Old description:
The file Test.hs has following definitions: {{{ whnf :: a -> IO () whnf a = a `seq` (return ())
foo :: [Int] foo = [1..] }}}
Calling ghci as: {{{ ghci Test.hs -ignore-dot-ghci }}}
and bebugging foo like this: {{{ *Main> :b foo Breakpoint 0 activated at Test.hs:5:7-11 *Main> foo Stopped at Test.hs:5:7-11 _result :: [Int] = _ [Test.hs:5:7-11] *Main> :p foo foo = (_t1::[Int]) [Test.hs:5:7-11] *Main> whnf _t1 }}}
results in this segault: {{{ <interactive>: internal error: TSO object entered! (GHC version 7.6.3 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [1] 5445 abort (core dumped) ghci Test.hs -ignore-dot-ghci }}}
New description: The file Test.hs has following definition: {{{ foo :: [Int] foo = [1..] }}} Calling ghci as: {{{ ghci Test.hs -ignore-dot-ghci }}} and bebugging foo like this: {{{ *Main> :break foo Breakpoint 0 activated at main.hs:2:7-11 *Main> foo Stopped in Main.foo, main.hs:2:7-11 _result :: [Int] = _ [main.hs:2:7-11] [main.hs:2:7-11] *Main> :print foo foo = (_t1::[Int]) [main.hs:2:7-11] [main.hs:2:7-11] *Main> _t1 }}} results in this segault: {{{ <interactive>: internal error: TSO object entered! (GHC version 8.5.20180302 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [1] 5445 abort (core dumped) ghci Test.hs -ignore-dot-ghci }}} -- Comment: I simplified example. whnf function is not required to trigger this bug. You can also notice that context of execution (i.e. [main.hs:2:7-11]) prints twice which looks like a bug and probably deserves a ticket. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8316#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler