Merge pull request #175365 from trofi/workaround-fno-common-for-tftp-hpa

tftp-hpa: add -fcommon workaround

pkgs/tools/networking/tftp-hpa/default.nix

···
     sha256 = "12vidchglhyc20znq5wdsbhi9mqg90jnl7qr9qs8hbvaz4fkdvmg";
   };
 
+  # Workaround build failure on -fno-common toolchains like upstream
+  # gcc-10. Otherwise build fails as:
+  #   ld: main.o:/build/tftp-hpa-5.2/tftp/main.c:98: multiple definition of
+  #     `toplevel'; tftp.o:/build/tftp-hpa-5.2/tftp/tftp.c:51: first defined here
+  NIX_CFLAGS_COMPILE="-fcommon";
+
   meta = with lib; {
     description = "TFTP tools - a lot of fixes on top of BSD TFTP";
     maintainers = with maintainers; [ raskin ];