How to build profiled stage1?

I'm trying to debug my stage1 compiler and as a last resort I'm trying to build stage1 compiler using `-prof -fprof-auto` to be able to do `+RTS -xc -RTS` during the stage2 build. I tried couple of things but they all failed in different ways. As far as I understand, both SRC_HC_OPTS and GhcStage1HcOpts are passed to system-wide installed ghc during the stage1 build and libraries. So I do one of these changes: SRC_HC_OPTS = -O -H64m -prof -fprof-auto GhcStage1HcOpts = -O0 -DDEBUG -prof -fprof-auto The second change I want to make is I want to pass `+RTS -xc -RTS` to ghc-stage1, for that I'm making this change: GhcLibHcOpts = -O -dcore-lint -prof -fprof-auto But, no matter what else I change, I can't get past this stage: "/usr/local/bin/ghc" -hisuf hi -osuf o -hcsuf hc -static -O -H64m -Wall -package-db libraries/bootstrapping.conf -this-package-key ghc-8.1 -hide-all-packages -i -icompiler/basicTypes -icompiler/cmm -icompiler/codeGen -icompiler/coreSyn -icompiler/deSugar -icompiler/ghci -icompiler/hsSyn -icompiler/iface -icompiler/llvmGen -icompiler/main -icompiler/nativeGen -icompiler/parser -icompiler/prelude -icompiler/profiling -icompiler/rename -icompiler/simplCore -icompiler/simplStg -icompiler/specialise -icompiler/stgSyn -icompiler/stranal -icompiler/typecheck -icompiler/types -icompiler/utils -icompiler/vectorise -icompiler/stage1/build -icompiler/stage1/build/autogen -Icompiler/stage1/build -Icompiler/stage1/build/autogen -Icompiler/. -Icompiler/parser -Icompiler/utils -Icompiler/stage1 -optP-include -optPcompiler/stage1/build/autogen/cabal_macros.h -package-id array-0.5.1.0-960bf9ae8875cc30355e086f8853a049 -package-id base-4.8.2.0-0d6d1084fbc041e1cded9228e80e264d -package-id binary-0.8.0.0 -package-id bytestring-0.10.6.0-9a873bcf33d6ce2fd2698ce69e2c1c66 -package-id containers-0.5.6.2-59326c33e30ec8f6afd574cbac625bbb -package-id directory-1.2.2.0-660a7a83a753ed85c8a374c15dae2b97 -package-id filepath-1.4.0.0-f97d1e4aebfd7a03be6980454fe31d6e -package-id ghc-boot-8.1 -package-id hoopl-3.10.2.1 -package-id hpc-0.6.0.3 -package-id process-1.2.3.0-a22328103774f0499a990653944cbf99 -package-id template-haskell-2.11.0.0 -package-id time-1.5.0.1-1b9a502bb07a3e6f4d6935fbf9db7181 -package-id transformers-0.5.0.0 -package-id unix-2.7.1.0-bb54ee8f9f6b2600aae7a748eb88a610 -Wall -fno-warn-name-shadowing -this-package-key ghc -XHaskell2010 -DSTAGE=1 -Rghc-timing -O0 -DDEBUG -prof -fprof-auto -no-user-package-db -rtsopts -odir compiler/stage1/build -hidir compiler/stage1/build -stubdir compiler/stage1/build -c compiler/utils/Exception.hs -o compiler/stage1/build/Exception.o compiler/utils/Exception.hs:10:1: Failed to load interface for ‘Control.Monad.IO.Class’ Perhaps you haven't installed the profiling libraries for package ‘transformers-0.5.0.0’? Use -v to see a list of the files searched for. <> I tried enabling library-profiling in my global Cabal config, but that didn't help. Any ideas how to do this? If it matters, I'm on Linux. NOTE: If I pass -v to GHC, it lists this place in the list of locations searched: /home/omer/haskell/ghc_unboxed_sums/libraries/transformers/dist-boot/build/Control/Monad/IO/Class.p_hi Indeed, the file is not there. When I look at all the command the build system run at this point, I see lines like this: "/usr/local/bin/ghc-pkg" update --force --package-db=libraries/bootstrapping.conf libraries/transformers/dist-boot/inplace-pkg-config Reading package info from "libraries/transformers/dist-boot/inplace-pkg-config" ... done. transformers-0.5.0.0: Warning: Unrecognized field abi on line 47 transformers-0.5.0.0: Warning: haddock-interfaces: /home/omer/haskell/ghc_unboxed_sums/libraries/transformers/dist-boot/doc/html/transformers/transformers.haddock doesn't exist or isn't a file transformers-0.5.0.0: cannot find any of ["Control/Applicative/Backwards.hi","Control/Applicative/Backwards.p_hi","Control/Applicative/Backwards.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Applicative/Lift.hi","Control/Applicative/Lift.p_hi","Control/Applicative/Lift.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Signatures.hi","Control/Monad/Signatures.p_hi","Control/Monad/Signatures.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Trans/Class.hi","Control/Monad/Trans/Class.p_hi","Control/Monad/Trans/Class.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Trans/Cont.hi","Control/Monad/Trans/Cont.p_hi","Control/Monad/Trans/Cont.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Trans/Except.hi","Control/Monad/Trans/Except.p_hi","Control/Monad/Trans/Except.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Trans/Error.hi","Control/Monad/Trans/Error.p_hi","Control/Monad/Trans/Error.dyn_hi"] (ignoring) transformers-0.5.0.0: cannot find any of ["Control/Monad/Trans/Identity.hi","Control/Monad/Trans/Identity.p_hi","Control/Monad/Trans/Identity.dyn_hi"] (ignoring) Then, after a while it's building transformers in a different way, using arguments like `-dep-makefile` etc. which are as far as I can see not documented in the GHC man page. When I look libraries/transformers I only see a directory named "dist-boot" with some weird files with ".haskell" extensions. I'm quite confused about how this is supposed to work. Can any of the build system experts help me here? This wiki page https://ghc.haskell.org/trac/ghc/wiki/Debugging/Compiler#Addingdebuggingcode... says "if you have built a profiling compiler ..." but it doesn't say anything about how to actually build it. Thanks.