Hi, I get the following error while compiling (I guess it's actually the linking step): $ghc -o cmimc cmimc.hs cmimc.o: In function `rP1_info': (.text+0x32a): undefined reference to `containerszm0zi2zi0zi1_DataziMap_zdf2_closure' cmimc.o: In function `rP3_info': (.text+0x396): undefined reference to `containerszm0zi2zi0zi1_DataziMap_zdf2_closure' cmimc.o: In function `rPh_info': (.text+0x666): undefined reference to `containerszm0zi2zi0zi1_DataziMap_fromList_closure' cmimc.o: In function `rPj_info': (.text+0x6ca): undefined reference to `containerszm0zi2zi0zi1_DataziMap_fromList_closure' cmimc.o: In function `sR5_info': (.text+0x1225): undefined reference to `__stginit_containerszm0zi2zi0zi1_DataziMap_' cmimc.o: In function `rP1_srt': (.data+0x90): undefined reference to `containerszm0zi2zi0zi1_DataziMap_zdf2_closure' cmimc.o: In function `rP3_srt': (.data+0xac): undefined reference to `containerszm0zi2zi0zi1_DataziMap_zdf2_closure' cmimc.o: In function `rPh_srt': (.data+0x15c): undefined reference to `containerszm0zi2zi0zi1_DataziMap_fromList_closure' cmimc.o: In function `rPj_srt': (.data+0x174): undefined reference to `containerszm0zi2zi0zi1_DataziMap_fromList_closure' collect2: ld returned 1 exit status However, running the program with ghci: $ghci cmimc.hs Prelude Main> :set args "testinput.txt" Prelude Main> :trace main gives the correct output... Where might there be a problem? In my installation (Kubuntu i386, ghc6.10.4-1ubunbtu2) perhaps? Please tell me if/which additional info I need to provide. TIA, Erik