Recompilation issue with cabal test

I'm not sure if this is a bug in ghc or in cabal.

Given four files:

repro.cabal

cabal-version:      3.0
name:               repro
version:            0.1.0.0
build-type:         Simple

library
  default-language: Haskell2010
  exposed-modules:
    Internal
    Process
  build-depends: base
  hs-source-dirs: src

test-suite repro
  default-language: Haskell2010
  type:          exitcode-stdio-1.0
  main-is:       Repro.hs
  build-depends: base, repro

Repro.hs

import Process (a)
import Internal (Unused)

main :: IO ()
main = a

src/Internal.hs

module Internal where

data Unused = Unused

b :: IO ()
b = return ()

src/Process.hs

module Process where

import Internal

a :: IO ()
a = b

1. Run cabal test
2. Remove last two lines in src/Internal.hs
3. Run cabal test. It will fail because b is no longer defined.
4. Restore the deleted lines in src/Internal.hs
5. Run cabal test. I expect this to succeed, but I get

Declaration for a
Unfolding of a:
  b1 ErrorWithoutFlag
       Can't find interface-file declaration for variable b1
         Probable cause: bug in .hi-boot file, or inconsistent .hi file
         Use -ddump-if-trace to get an idea of which file caused the error
<no location info>: error:
    Cannot continue after interface file error

I've found this when looking at #24924 but it should be independent. Reproduced with 9.8.2 and 9.10.1. Doesn't happen if import Internal (Unused) is removed.