code: def build(ctx, builder="html", options=""):
      
      sourcedir = ctx.config.sphinx.sourcedir
      destdir = Path(ctx.config.sphinx.destdir or "build")/builder
      destdir = destdir.abspath()
      with cd(sourcedir):
          destdir_relative = Path(".").relpathto(destdir)
          command = "sphinx-build {opts} -b {builder} {sourcedir} {destdir}" \
                      .format(builder=builder, sourcedir=".",
                              destdir=destdir_relative, opts=options)
          ctx.run(command)
docs: Build docs with sphinx-build