The configure file in subversion-1.2.3-3 looks for swig of at least 1.3.24 to
build the Ruby bindings. Without this, SWIG_RB_COMPILE in the Makefile is set to
"none", which of course fails the build.
Alas, we seem to be condemned to repeat history:
Fixed in 1.2.3-5, thanks for the report.