use of $USER in configure script crashes if $USER has an invalid token

[elee]

My login is 'eric.lee' on a machine I'm trying to ./configure node-jscoverage on

This seems to upset ./configure when it tries to create a C preprocessor define #DEBUG_eric.lee

because '.' is an invalid token for a preprocessor #{,un}define in C

configure log output: https://gist.github.com/3842533

using latest, i.e. https://github.com/visionmedia/node-jscoverage/commit/36b3ba5d82a87ffe45ae7101b7b036a3cb25483e

[elee]

workaround, just reassign $USER and re-run ./configure

i.e.

 $ echo $USER
 foo.bar
 $ USER = foobar
 $ ./configure