Fix misc errors, stop needing a Nix change

doc/manual/meson.build

@@ -30,7 +30,7 @@ nix_eval_for_docs_common = nix_for_docs + [
 nix_eval_for_docs = nix_eval_for_docs_common + '--raw'
 
 conf_file_json = custom_target(
-  command : nix_for_docs + ['show', 'config', '--json'],
+  command : nix_for_docs + ['config', 'show', '--json'],
   capture : true,
   output : 'conf-file.json',
   env : nix_env_for_docs,

doc/manual/remove_before_wrapper.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+
+import os
+import subprocess
+import sys
+import shutil
+import typing as t
+
+def main():
+    if len(sys.argv) < 4 or '--' not in sys.argv:
+        print("Usage: remove-before-wrapper <output> -- <nix command...>")
+        sys.exit(1)
+
+    # Extract the parts
+    output: str = sys.argv[1]
+    nix_command_idx: int = sys.argv.index('--') + 1
+    nix_command: t.List[str] = sys.argv[nix_command_idx:]
+
+    output_temp: str = output + '.tmp'
+
+    # Remove the output and temp output in case they exist
+    shutil.rmtree(output, ignore_errors=True)
+    shutil.rmtree(output_temp, ignore_errors=True)
+
+    # Execute nix command with `--write-to` tempary output
+    nix_command_write_to = nix_command + ['--write-to', output_temp]
+    subprocess.run(nix_command_write_to, check=True)
+
+    # Move the temporary output to the intended location
+    os.rename(output_temp, output)
+
+if __name__ == "__main__":
+    main()

doc/manual/src/command-ref/meson.build

@@ -19,12 +19,17 @@ experimental_features_shortlist_md = custom_target(
 )
 
 nix3_cli_files = custom_target(
-  command : nix_eval_for_docs_common + [
-    '--write-to', '@OUTPUT@',
+  command : [
+    python.full_path(),
+    '@INPUT0@',
+    '@OUTPUT@',
+    '--'
+  ] + nix_eval_for_docs + [
     '--expr',
-    'import @INPUT0@ true (builtins.readFile ./@INPUT1@)',
+    'import @INPUT1@ true (builtins.readFile ./@INPUT2@)',
   ],
   input : [
+    '../../remove_before_wrapper.py',
     '../../generate-manpage.nix',
     nix3_cli_json,
   ],

doc/manual/src/language/meson.build

@@ -1,10 +1,15 @@
 builtins_md = custom_target(
-  command : nix_eval_for_docs + [
-    '--write-to', '@OUTPUT@',
+  command : [
+    python.full_path(),
+    '@INPUT0@',
+    '@OUTPUT@',
+    '--'
+  ] + nix_eval_for_docs + [
     '--expr',
-    '(builtins.readFile @INPUT2@) + import @INPUT0@ (builtins.fromJSON (builtins.readFile ./@INPUT1@)) + (builtins.readFile @INPUT3@)',
+    '(builtins.readFile @INPUT3@) + import @INPUT1@ (builtins.fromJSON (builtins.readFile ./@INPUT2@)) + (builtins.readFile @INPUT4@)',
   ],
   input : [
+    '../../remove_before_wrapper.py',
     '../../generate-builtins.nix',
     language_json,
     'builtins-prefix.md',

doc/manual/src/store/meson.build

@@ -1,10 +1,15 @@
 types_dir = custom_target(
-  command : nix_eval_for_docs + [
-    '--write-to', '@OUTPUT@',
+  command : [
+    python.full_path(),
+    '@INPUT0@',
+    '@OUTPUT@',
+    '--'
+  ] + nix_eval_for_docs + [
     '--expr',
-    'import @INPUT0@ (builtins.fromJSON (builtins.readFile ./@INPUT1@)).stores',
+    'import @INPUT1@ (builtins.fromJSON (builtins.readFile ./@INPUT2@)).stores',
   ],
   input : [
+    '../../remove_before_wrapper.py',
     '../../generate-store-types.nix',
     nix3_cli_json,
   ],

doc/manual/substitute.py

@@ -4,10 +4,11 @@
 import json
 import os, os.path
 import sys
+import typing as t
 
 name = 'substitute.py'
 
-def log(*args: Any, **kwargs: Any) -> None:
+def log(*args: t.Any, **kwargs: t.Any) -> None:
     kwargs['file'] = sys.stderr
     print(f'{name}:', *args, **kwargs)
 
@@ -34,7 +35,7 @@ def do_include(content: str, relative_md_path: Path, source_root: Path, search_p
             lines.append(l)
     return "".join(lines)
 
-def recursive_replace(data: dict[str, Any], book_root: Path, search_path: Path) -> dict[str, Any]:
+def recursive_replace(data: dict[str, t.Any], book_root: Path, search_path: Path) -> dict[str, t.Any]:
     match data:
         case {'sections': sections}:
             return data | dict(

src/nix/eval.cc

@@ -11,8 +11,6 @@
 
 using namespace nix;
 
-namespace nix::fs { using namespace std::filesystem; }
-
 struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
 {
     bool raw = false;
@@ -77,8 +75,8 @@ struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
         if (writeTo) {
             stopProgressBar();
 
-            //if (pathExists(*writeTo))
-            //    throw Error("path '%s' already exists", *writeTo);
+            if (pathExists(*writeTo))
+                throw Error("path '%s' already exists", *writeTo);
 
             std::function<void(Value & v, const PosIdx pos, const std::filesystem::path & path)> recurse;
 
@@ -89,8 +87,8 @@ struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
                     // FIXME: disallow strings with contexts?
                     writeFile(path.string(), v.string_view());
                 else if (v.type() == nAttrs) {
-                    // N.B. this is idempotent
-                    fs::create_directory(path.string());
+                    // TODO abstract mkdir perms for Windows
+                    createDir(path.string(), 0777);
                     for (auto & attr : *v.attrs()) {
                         std::string_view name = state->symbols[attr.name];
                         try {