I should mention that I converted the recipe from Nix [1] which has
different hashes for patches.
--8<---------------cut here---------------start------------->8---
  patches =
    let fetchAlpinePatch = name: sha256: fetchpatch {
      url = "https://git.alpinelinux.org/cgit/aports/plain/main/net-snmp/${name}?id=f25d3fb08341b60b6ccef424399f060dfcf3f1a5";
      inherit name sha256;
    };
  in [
    (fetchAlpinePatch "CVE-2015-5621.patch" "05098jyvd9ddr5q26z7scbbvk1bk6x4agpjm6pyprvpc1zpi0y09")
    (fetchAlpinePatch "fix-Makefile-PL.patch" "14ilnkj3cr6mpi242hrmmmv8nv4dj0fdgn42qfk9aa7scwsc0lc7")
    (fetchAlpinePatch "fix-includes.patch" "0zpkbb6k366qpq4dax5wknwprhwnhighcp402mlm7950d39zfa3m")
    (fetchAlpinePatch "netsnmp-swinst-crash.patch" "0gh164wy6zfiwiszh58fsvr25k0ns14r3099664qykgpmickkqid")
    (fetchAlpinePatch "remove-U64-typedef.patch" "1msxyhcqkvhqa03dwb50288g7f6nbrcd9cs036m9xc8jdgjb8k8j")
  ];
--8<---------------cut here---------------end--------------->8---

[1]  https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/monitoring/net-snmp/default.nix#L11

Oleg.