GNU Make: No rule to make target `mocha.css'

[joliss]

With GNU Make 3.81, mocha.js rebuilds fine, but mocha.css doesn't:

$ make clean; make all
rm -f mocha.js mocha.css
rm -fr lib-cov
rm -f coverage.html
make: *** No rule to make target `mocha.css', needed by `all'.  Stop.
make: *** Waiting for unfinished jobs....

  compile : lib/browser/diff.js
  compile : lib/browser/fs.js
  compile : lib/browser/path.js
  compile : lib/browser/debug.js
  compile : lib/browser/events.js
  compile : lib/browser/progress.js
  compile : lib/browser/tty.js
  compile : lib/context.js
  compile : lib/hook.js
  compile : lib/interfaces/bdd.js
  compile : lib/interfaces/exports.js
  compile : lib/interfaces/index.js
  compile : lib/interfaces/qunit.js
  compile : lib/interfaces/tdd.js
  compile : lib/mocha.js
  compile : lib/reporters/base.js
  compile : lib/reporters/doc.js
  compile : lib/reporters/dot.js
  compile : lib/reporters/html-cov.js
  compile : lib/reporters/html.js
  compile : lib/reporters/index.js
  compile : lib/reporters/json-cov.js
  compile : lib/reporters/json-stream.js
  compile : lib/reporters/json.js
  compile : lib/reporters/landing.js
  compile : lib/reporters/list.js
  compile : lib/reporters/markdown.js
  compile : lib/reporters/min.js
  compile : lib/reporters/progress.js
  compile : lib/reporters/spec.js
  compile : lib/reporters/tap.js
  compile : lib/reporters/teamcity.js
  compile : lib/reporters/xunit.js
  compile : lib/runnable.js
  compile : lib/runner.js
  compile : lib/suite.js
  compile : lib/test.js
  compile : lib/utils.js
   create : mocha.js