Fix include paths for Nix headers

While the previous style seems more sensible to me (the header names
are quite generic), the pkg-config definitions both from upstream Nix
and from Lix specify -I${includedir}/nix in CFLAGS rather than
-I${includedir}. This may be worth changing, but for now I want
nix-eval-jobs to work and this does what I want.

src/eval-args.cc

@@ -1,9 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <nix/args.hh>
+#include <args.hh>
-#include <nix/file-system.hh>
+#include <flake/flake.hh>
-#include <nix/flake/flake.hh>
+#include <flake/lockfile.hh>
-#include <nix/flake/lockfile.hh>
 #include <functional>
 #include <map>
 #include <memory>

src/nix-eval-jobs.cc

@@ -1,11 +1,10 @@
 #include <nix/config.h> // IWYU pragma: keep
 
-#include <nix/eval-settings.hh>
+#include <eval-settings.hh>
-#include <nix/shared.hh>
+#include <shared.hh>
-#include <nix/sync.hh>
+#include <sync.hh>
-#include <nix/eval.hh>
+#include <eval.hh>
-#include <nix/signals.hh>
+#include <signals.hh>
-#include <nix/terminal.hh>
 #include <sys/wait.h>
 #include <nlohmann/json.hpp>
 #include <errno.h>
@@ -13,18 +12,16 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <nix/attr-set.hh>
+#include <attr-set.hh>
-#include <nix/config.hh>
+#include <config.hh>
-#include <nix/error.hh>
+#include <error.hh>
-#include <nix/file-descriptor.hh>
+#include <globals.hh>
-#include <nix/globals.hh>
+#include <logging.hh>
-#include <nix/logging.hh>
 #include <nlohmann/detail/iterators/iter_impl.hpp>
 #include <nlohmann/detail/json_ref.hpp>
 #include <nlohmann/json_fwd.hpp>
-#include <nix/processes.hh>
+#include <ref.hh>
-#include <nix/ref.hh>
+#include <store-api.hh>
-#include <nix/store-api.hh>
 #include <map>
 #include <thread>
 #include <condition_variable>

src/worker.cc

@@ -3,35 +3,32 @@
 // doesn't exist on macOS
 // IWYU pragma: no_include <bits/types/struct_rusage.h>
 
-#include <nix/terminal.hh>
+#include <attr-path.hh>
-#include <nix/attr-path.hh>
+#include <local-fs-store.hh>
-#include <nix/local-fs-store.hh>
+#include <installable-flake.hh>
-#include <nix/installable-flake.hh>
 #include <sys/resource.h>
 #include <nlohmann/json.hpp>
 #include <stdio.h>
 #include <stdlib.h>
-#include <nix/attr-set.hh>
+#include <attr-set.hh>
-#include <nix/canon-path.hh>
+#include <canon-path.hh>
-#include <nix/common-eval-args.hh>
+#include <common-eval-args.hh>
-#include <nix/error.hh>
+#include <error.hh>
-#include <nix/eval-inline.hh>
+#include <eval-inline.hh>
-#include <nix/eval.hh>
+#include <eval.hh>
-#include <nix/file-descriptor.hh>
+#include <flake/flakeref.hh>
-#include <nix/file-system.hh>
+#include <get-drvs.hh>
-#include <nix/flake/flakeref.hh>
+#include <input-accessor.hh>
-#include <nix/get-drvs.hh>
+#include <logging.hh>
-#include <nix/input-accessor.hh>
+#include <nixexpr.hh>
-#include <nix/logging.hh>
-#include <nix/nixexpr.hh>
 #include <nlohmann/detail/json_ref.hpp>
 #include <nlohmann/json_fwd.hpp>
-#include <nix/ref.hh>
+#include <ref.hh>
-#include <nix/store-api.hh>
+#include <store-api.hh>
-#include <nix/symbol-table.hh>
+#include <symbol-table.hh>
-#include <nix/types.hh>
+#include <types.hh>
-#include <nix/util.hh>
+#include <util.hh>
-#include <nix/value.hh>
+#include <value.hh>
 #include <exception>
 #include <map>
 #include <memory>