Backpack panic: Duplicate nodes keys in backpack file
Consider this .bkp
file:
unit p where
signature H where
unit q where
module H where
unit r where
dependency p
dependency q[H=p:H]
There's a mistake: we mixed up p
and q
in the unit r
.
This causes the following panic:
ghc: panic! (the 'impossible' happened)
GHC version 9.7.20230504:
Duplicate nodes keys in backpack file
[q+q-9dU7VXZcSfk3MwGleJHyst:H, q+q-9dU7VXZcSfk3MwGleJHyst:H]
I am inclined to believe this is a bkpism (affects only the .bkp
format and not cabal
projects that use Backpack), but I haven't checked.