LGTM, and some minor nits.
https://codereview.appspot.com/575860044/diff/547790043/aclocal.m4 File aclocal.m4 (right): https://codereview.appspot.com/575860044/diff/547790043/aclocal.m4#newcode625 aclocal.m4:625: AC_ARG_VAR(GUILE_FLAVOR, AS_HELP_STRING([], What about breaking the line here to get shorter lines? https://codereview.appspot.com/575860044/diff/547790043/aclocal.m4#newcode630 aclocal.m4:630: AC_ARG_VAR(GUILE_CONFIG, [guile-config executable, obsoleted by pkgconfig/GUILE_FLAVOR])dnl Ditto. https://codereview.appspot.com/575860044/diff/547790043/aclocal.m4#newcode640 aclocal.m4:640: AC_MSG_ERROR([\$GUILE_CONFIG info guileversion failed: $tmp_GUILE_FLAVOR]) For consistency I suggest to add `;;` here, too. https://codereview.appspot.com/575860044/
