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GHCi debugger panics when trying force a certain variable

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> :print foo
foo = (_t1::[Int])
[main.hs:2:7-11] *Main> _t1

results in this panic:

<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
Edited by Ömer Sinan Ağacan
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