liblognorm contains a garbled line in configure.ac that went undetected so far because over-linking with -lrt is harmless: AC_SEARCH_LIBS(clock_getm4_defn([AC_AUTOCONF_VERSION]), [2.68]time, rt) It should read: AC_SEARCH_LIBS(clock_gettime, rt) This came up in the Fedora C99 porting effort (https://fedoraproject.org/wiki/Toolchain/PortingToModernC https://fedoraproject.org/wiki/Changes/PortingToModernC) because it happens to introduce an implicit function declaration into the generated conftest.c file. This means it raises a red flag in the tester we use for porting, so it would be good to fix configure.ac and regenerate configure. I reported this through Adiscon using the liblognorm contact link. Adiscon assigned internal ticket number 6711. There does not seem to be a public version control repository or bug tracker, so I'm filing it here for a public reference.