I guess I should get back to this bug report at least once a year.  I'm trying to understand how Scheme handles eval.  If I look at R5RS or R6RS, I see that the eval procedure takes an environment as an argument.  The procedures that create environment all seem to create variants of the top-level environment (an empty environment, the interactive environment, etc.).  I don't see any way to create an environment that contains the bindings visible in a particular region of code.  Am I missing something?