Dear ghc-5.02-linux-i386-unknown, You understand extra_ghc_opts = ["-v","-O"] when using a package, but not extra_ghc_opts = ["-v -O"] And I intended to set in Makefile ... ex = -ddump-hi-diffs -fglasgow-exts -fallow-overlapping-instances -fallow-undecidable-instances -fno-warn-overlapping-patterns -fwarn-unused-binds -fwarn-unused-matches -fwarn-unused-imports ... pk = Package {... extra_ghc_opts = ["\"$(ex)\""], ... } ... echo $(pk) | ghc-pkg -a What may be a reasonable way out? ----------------- Serge Mechveliani mechvel@botik.ru