Use boost::format from the boost package

Note that this only requires headers from boost so it doesn't add a
runtime dependency.

Also, use Nixpkgs 18.03.

Makefile

@@ -1,6 +1,5 @@
 makefiles = \
  local.mk \
- src/boost/format/local.mk \
  src/libutil/local.mk \
  src/libstore/local.mk \
  src/libmain/local.mk \

local.mk

@@ -10,5 +10,3 @@ GLOBAL_CXXFLAGS += -I . -I src -I src/libutil -I src/libstore -I src/libmain -I
 
 $(foreach i, config.h $(call rwildcard, src/lib*, *.hh), \
  $(eval $(call install-file-in, $(i), $(includedir)/nix, 0644)))
-
-$(foreach i, $(call rwildcard, src/boost, *.hpp), $(eval $(call install-file-in, $(i), $(includedir)/nix/$(patsubst src/%/,%,$(dir $(i))), 0644)))

release.nix

@@ -1,5 +1,5 @@
 { nix ? builtins.fetchGit ./.
-, nixpkgs ? builtins.fetchGit https://github.com/NixOS/nixpkgs.git
+, nixpkgs ? builtins.fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-18.03"; }
 , officialRelease ? false
 , systems ? [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ]
 }:
@@ -71,6 +71,7 @@ let
  [ curl
  bzip2 xz brotli
  openssl pkgconfig sqlite boehmgc
+ boost
 
  # Tests
  git
@@ -192,7 +193,7 @@ let
 
  doInstallCheck = true;
 
- lcovFilter = [ "*/boost/*" "*-tab.*" "*/nlohmann/*" "*/linenoise/*" ];
+ lcovFilter = [ "*-tab.*" "*/nlohmann/*" "*/linenoise/*" ];
 
  # We call `dot', and even though we just use it to
  # syntax-check generated dot files, it still requires some

shell.nix

@@ -1,6 +1,6 @@
 { useClang ? false }:
 
-with import <nixpkgs> {};
+with import (builtins.fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-18.03"; }) {};
 
 with import ./release-common.nix { inherit pkgs; };
 
@@ -18,6 +18,7 @@ with import ./release-common.nix { inherit pkgs; };
  customMemoryManagement = false;
  })
  autoreconfHook
+ boost
 
  # For nix-perl
  perl