Application linking problem with lesstif

[pierre.baudon]

I have an error with ld concerning the "-lXm" option when I compile my application. When I look at the path in which gnorpm installed lesstif (and which is declared using ldconfig before compiling), I can not find the file "libXm.a", I just have "libXm.la".   I tried to install lesstif libc5 without rpm in an other directory, with the same result ("libXm.a" does not exist, but "libXm.la" does).   I don't understand what happens. What should I check or do?