***** aclocal *****
***** PWD: /var/tmp/portage/sci-geosciences/gpsbabel-1.3.6/work/gpsbabel-1.3.6
***** aclocal

configure.in:39: error: AC_SUBST: `' is not a valid shell variable name
configure.in:39: the top level
autom4te-2.63: /usr/bin/gm4 failed with exit status: 1
aclocal-1.10: autom4te failed with exit status: 1