QA: prepare This package has a configure.in file which has long been deprecated. Please update it to use configure.ac instead as newer versions of autotools will die when it finds this file. See https://bugs.gentoo.org/426262 for details.
Virtually everything mozilla uses autoconf-2.13, including firefox, thunderbird, etc. We also already peg the version with WANT_AUTOCONF in the nspr, nss, firefox, and thunderbird ebuilds, which should mean that those newer versions of autotools won't ever see the build systems in these packages, correct?
Correction, nspr uses >=autoconf-2.61 rather than 2.1* , so yes this package does indeed need fixing. I've addressed this in nspr-4.10.{8,9} via a rename of configure.in to configure.ac.