2.31.91 was released a couple of weeks ago. There are some missing dependencies in the in-tree ebuild, and no auxiliary documentation is installed. Attaching an ebuild patch and simple-scan patch for 2.31.91.
Created attachment 246947 [details, diff] ebuild patch
Created attachment 246948 [details, diff] patch to configure with older (<1.2.5) zlib version
(In reply to comment #0) > 2.31.91 was released a couple of weeks ago. Two weeks don't sound like 'a couple' :P.
David, thank you for the ebuild. Did you send your patch to upstream developers? I 've added the new ebuild on tree. Thank you for your improvements.
(In reply to comment #4) > David, thank you for the ebuild. Did you send your patch to upstream > developers? No, I took the patch from the Debian package for simple-scan, but I reported a bug upstream and attached the patch, thanks for the suggestion: https://bugs.launchpad.net/simple-scan/+bug/637938