a few improvements -> build is successful

- GCC build was failing with warnings/errors for printf. NixOS disables
  hardening for format and pie for gcc so we do the same.
- gdb is built with Python support. The configure check for Python also
  uses -lncurses so we need that as well. The message is rather
  confusing because it claims not to find Python.

.gitignore

+/x/

esp32-tools.nix

-{ lib, stdenv, fetchurl, fetchgit, fetchFromGitHub, espressif-crosstool-ng, autoconf, automake, bison, flex, unzip, help2man, libtool, which, texinfo, file, wget, gnum4, perl }:
+{ lib, stdenv, fetchurl, fetchgit, fetchFromGitHub, espressif-crosstool-ng, autoconf, automake, bison, flex, unzip, help2man, libtool, which, texinfo, file, wget, gnum4, perl, ncurses, python3 }:
 let
   srcs = import ./sources.nix { inherit fetchFromGitHub; };
   srcs2 = import ./sources2.nix { inherit fetchurl fetchgit fetchFromGitHub; };
@@ -9,7 +9,10 @@ in stdenv.mkDerivation {
   additionalSources = lib.strings.concatStringsSep "\n"
     (lib.attrsets.mapAttrsToList (name: drv: if drv ? outPath then "${name} ${drv.outPath}" else "") srcs2);
 
-  nativeBuildInputs = [ espressif-crosstool-ng autoconf automake bison flex unzip help2man libtool which texinfo file wget gnum4 perl ];
+  buildInputs = [ ncurses python3 ];
+  nativeBuildInputs = [ espressif-crosstool-ng autoconf automake bison flex unzip help2man libtool which texinfo file wget gnum4 perl python3 ];
+
+  hardeningDisable = [ "format" "pie" ];
 
   dontConfigure = true;
   dontInstall = true;
@@ -22,7 +25,7 @@ in stdenv.mkDerivation {
     echo "CT_FORBID_DOWNLOAD=y" >>.config
     mkdir tarballs
     while read name path ; do
-      printf "%-20s -> %s" $name $path
+      printf "%-30s -> %s\\n" $name $path
       if [ -d $path ] ; then
         # ugly but works...
         cp -aHT $path tarballs/$name
@@ -33,6 +36,9 @@ in stdenv.mkDerivation {
       fi
     done <<<"$additionalSources"
 
+    # for debugging, see `ct-ng list-steps`
+    #export CT_DEBUG_CT_SAVE_STEPS=y
+
     CT_USE_SOURCES_FROM_NIXOS=y \
       ct-ng build \
       || ( tail -n 100 build.log ; exit 1 )