runhaskell Setup register fails with "internal error: unexpected package db stack"

I built 6.12.2 using the already installed (and working) ghc-6.12.1. I built ghc-6.12.2 using the same procedure as 6.12.1, so it's unlikely to be caused by build procedure changes. If I try to compile packages using the new version everything works fine until I try to generate the register.sh script:

$ tar xf zlib-0.5.2.0.tar.gz
$ runhaskell Setup configure --prefix=/usr --libdir=/usr/lib64 \
    --docdir=/usr/share/doc/zlib-0.5.2.0 \
    --htmldir=/usr/share/doc/zlib-0.5.2.0/html \
    --with-compiler=ghc-6.12.2 --enable-shared \
    --disable-executable-stripping --global --verbose \
    --disable-library-profiling
$ runhaskell Setup build
$ runhaskell Setup copy --destdir=$PWD/install-root/
$ runhaskell Setup register --global --gen-script
Creating package registration script: register.sh
Setup: internal error: unexpected package db stack

This happens with every package I tried to far. Could someone help me narrow this problem down?

Trac metadata

Trac field	Value
Version	6.12.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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