I'm trying to build yhc on my debian machine. When I'm executing scons build, it reports the following error: $ scons build scons: Reading SConscript files ... Building version 0.7.0-20061129043224-custom. Checking for architecture... (cached) x86 Checking for operating system... (cached) linux2 Checking for C header file gmp.h... (cached) yes Checking for mpz_t integ; mpz_init (integ) in C library gmp... (cached) yes Checking for libgmp version... (cached) Bootstrapping... build/SConscript.depends -> depends/SConscript build/SConscript.cpphs -> depends/cpphs/SConscript build/SConscript.filepath -> depends/filepath/SConscript build/SConscript.ctypes -> depends/ctypes/SConscript build/SConscript.libffi -> depends/ctypes/libffi/SConscript build/ffih/fficonfig.h -> depends/ctypes/libffi/fficonfig.h build/ffih/ffi.h -> depends/ctypes/libffi/include/ffi.h build/ffih/cfield.c -> depends/ctypes/libffi/src/cfield.c bootstrap/packages/yhc-base/1.0/Prelude.hi -> src/packages/yhc-base-1.0/Prelude.hi bootstrap/packages/yhc-base/1.0/PreludeBuiltin.hi -> src/packages/yhc-base-1.0/PreludeBuiltin.hi bootstrap/packages/yhc-base/1.0/YHC/Internal.hi -> src/packages/yhc-base-1.0/YHC/Internal.hi bootstrap/packages/yhc-base/1.0/Data/Ratio.hi -> src/packages/yhc-base-1.0/Data/Ratio.hi Done. scons: done reading SConscript files. scons: Building targets ... Getting dependencies for src/compiler98/Bind.hs. Getting dependencies for src/compiler98/Util/Text.hs. ghc -i./src/compiler98 -i./src/libraries/general -i./src/libraries/core -idepends/cpphs -idepends/filepath -i./src/interactive -package mtl -fwarn-missing-signatures -c src/compiler98/Util/Text.hs -o src/compiler98/Util/Text.o ghc-6.6: unknown package: mtl scons: *** [src/compiler98/Util/Text.o] Error 1 scons: building terminated because of errors. What's the problem? Can anyone help me with it?