http://mail-index.netbsd.org/tech-pkg/2006/07/30/0005.html
2. Too much is logged in the .wrapper.log
The wrappers log quite a lot of detailed information by
default, with the result that my .work.log file is 176236028
bytes {for ghc}.
The wrapper functionality is mature, so this detailed
information is seldom needed, and you can in general determine
what happened by looking at the input/output-lines (i.e.
those lines marked as "[*]" and "<.>" in the .work.log).
I would therefore like to change the default behavior to
only log the input/output-lines.
Flip the switch for WRAPPER_DEBUG from "yes" to "no" by default so
that the detailed and rather verbose "push", "pop", "transform", etc.
messages are not printed. While here, also make WRAPPER_DEBUG a
pkgsrc-private variable by prepending with an underscore.