Hi Nick, Command line arguments to gcc are processed in the order specified, one at a time. One pass. Object files are taken in their entirety. Archive files only use the internal object files which satisfy outstanding unfulfilled symbols. Since you are specifying your .c file (which gets compiled into a .o file) AFTER your libraries, your library does not get used because at the time the library is processed there are no outstanding unfulfilled symbols. Try reordering your command line so that items with dependencies are BEFORE those things that fulfill those dependencies. E.g. ... gcc -v -Wall -Wextra -g \ -o clue-keygen \ -I/usr/local/include/pbc -I../include \ -L/home/someguy/clue/lib -L/usr/local/lib \ clue-keygen.c \ -lgmp -lpbc -lpbc_sig -lclue I'm not sure of the order of gmp, pbc, pbc_sig and clue. Just guessing. FYI/Note: -Wextra has replaced deprecated -W ... I'm not sure if that occurred by 3.4.4. The -Wblahblahblah I've been using recently for my C++ code are... -Wmost (like -Wall, excluding -Wparentheses) -Wextra -W#warning -Wmissing-format-attribute -Wmissing-noreturn -Wpacked -Wshadow -Wcast-align -Wcast-qual -Wconversion -Wdeprecated -Wdeprecated-declarations -Wendif-labels -Wformat-extra-args -Winline -Winvalid-offsetof -Wnon-lvalue-assign -Wnon-virtual-dtor -Woverloaded-virtual -Wpmf-conversions -Wpointer-arith -Wshorten-64-to-32 -Wsign-compare -Wsign-promo -Wwrite-strings -Wunreachable-code Ones that I don't use but would like to enable... -Wfloat-equal -Wold-style-cast Ones that I haven't decided yet... -Weffc++ -Wnon-template-friend -Wnormalized=id -Wredundant-decls HTH, --Eljay
