It's needed by current gnupg git HEAD and will probably be a dependency of >=app-crypt/gnupg-2.1.0, when that gets released. Reproducible: Always
Created attachment 351608 [details] npth-0.91.ebuild Works for me. After a quick read of configure.ac I didn't see any non-libc dependencies.
Created attachment 351610 [details] npth-0.91.ebuild Add IUSE="static-libs". Use ${PV} instead of hardcoded version.
It will be great to get rid of the pth library. We wait until gnupg release that actually use this.
This has been in the tree for a while.