Unused variables in tree-bind forms are not generating diagnostics with source location info. We are missing some rlcp calls. * stdlib/compiler.tl (compiler comp-catch): The generated lambda here ends up transformed to a let by the lambda-apply-transfom function. We must propagate source info to it, otherwise unused catch clause parameters get diagnosed without it. (compiler (comp-for, comp-mac-param-bind, comp-mac-env-param-bind, comp-tree-case): Confer source location info onto the err-form argument of expand-bind-mac-params. (expand-bind-mac-params): Pass source location info from err-form onto the generated let* form. Thus, diagnostics related to variables in that let* get reported against that form's location. (lambda-apply-transform): Pass source location info from the lambda expression to the generated let. * stdlib/except.tl (usr:catch): Pass source loc info from each clause source code to the transformed clause. The transformed clause will turn into a lambda which will turn into a let in comp-catch, and then into a let in lambda-apply-transform.