Followup: I managed to get things configured to work with `cabal v2-build`, and with this build, the app dumps STG code as expected. I am unblocked! Norman
nr@homedog ~/a/sandbox> cabal v1-build Resolving dependencies... Configuring sandbox-0.1.0.0... Preprocessing executable 'sandbox' for sandbox-0.1.0.0.. Building executable 'sandbox' for sandbox-0.1.0.0.. [1 of 1] Compiling Main ( app/Main.hs, dist/build/sandbox/sandbox-tmp/Main.o ) [Source file changed] Linking dist/build/sandbox/sandbox ... nr@homedog ~/a/sandbox> ./dist/build/sandbox/sandbox programs/Church.hs libdir == /home/nr/asterius/ghc/_build/stage1/lib ModSummary { ms_hs_hash = 8ed607a72dd3968f1e65123b865b8572 ms_mod = Church, ms_textual_imps = [(Nothing, Prelude)] ms_srcimps = [] } .............. sandbox: panic! (the 'impossible' happened) GHC version 9.3.20210918: unsafeGetHomeUnit: No home unit
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug