"Error: symbol `__stg_split_marker' is already defined"

Hi,

I'm trying to compile (a modified version of) HSQL and the compilation
fails on the first ghc invocation:

...
rm -f build/libHSsql.a
cp src/HSQL/Types.hs build/Database/HSQL/Types.hs
mkdir -p build/Database/HSQL/Types_split
rm -f build/Database/HSQL/Types_split/*
/usr/bin/ghc build/Database/HSQL/Types.hs -O -c -ibuild -fglasgow-exts 
-split-objs -I/home/frederik/include/mysql -Isrc/HSQL -package-name hsql
/tmp/ghc12887.s: Assembler messages:
/tmp/ghc12887.s:99: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:194: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:289: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:384: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:479: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:574: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:669: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:764: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:859: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:954: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:1049: Error: symbol `__stg_split_marker' is already defined
...
/tmp/ghc12887.s:19629: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:19653: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:19677: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:19721: Error: symbol `__stg_split_marker' is already defined
/tmp/ghc12887.s:19765: Error: symbol `__stg_split_marker' is already defined
make: *** [build/Database/HSQL/Types.o] Error 1

What causes this __stg_split_marker error, what does it indicate?

Thanks,

Frederik