In systems using a GNU toolchain (i.e. using glibc, binutils, etc, such as GNU/Linux, GNU/Hurd and GNU/kFreeBSD), the linking of scite/gtk needs to explicitly add the dl library, since dlopen/dlclose are used by the lua sources.
scite/gtk/makefile already appends -ldl on Linux, attached there is a patch to do the same on other GNU systems.
Committed as [b7c517].
Related
Commit: [b7c517]