If you build a Cactus configuration using
make <configname>-config <option1>=<value1> <option2>=<value2>
the <value1>... get spaces added to them in configs/<configname>/config-info. This does not happen if you use options from a file. Depending on how the variables are used, this extra space at the end can be a problem (e.g. it causes problems with GSL_DIR, as the GSL script doesn't expect whitespace at the end of the variable).
I traced this to a greedy regular expression in setup_configuration.pl. The attached patch fixes the problem, but has not been tested extensively.