Start on 3.3.0

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 1a3a94b5ee041693f56f2e5eed227cdfa4a02e75..40ebf1b6248c121b1775cb2b36df3580e91334c9 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -320,22 +320,12 @@ def digest_file(filename: str) -> Digest16:
     return Digest16(hasher.hexdigest())
 
 
-@functools.lru_cache
-def _experimental_flag_needed(v: Verification) -> bool:
-    v.status('Checking Nix version')
-    process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE)
-    v.result(process.returncode == 0)
-    return b'--experimental-features' in process.stdout
-
-
-def _nix_command(v: Verification) -> List[str]:
-    return ['nix', '--experimental-features',
-            'nix-command'] if _experimental_flag_needed(v) else ['nix']
+_NIX_COMMAND = ['nix', '--experimental-features', 'nix-command']
 
 
 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
     v.status('Converting digest to base16')
-    process = subprocess.run(_nix_command(v) + [
+    process = subprocess.run(_NIX_COMMAND + [
         'to-base16',
         '--type',
         'sha256',
@@ -347,7 +337,7 @@ def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
 
 def to_Digest32(v: Verification, digest16: Digest16) -> Digest32:
     v.status('Converting digest to base32')
-    process = subprocess.run(_nix_command(v) + [
+    process = subprocess.run(_NIX_COMMAND + [
         'to-base32',
         '--type',
         'sha256',
@@ -685,23 +675,35 @@ def updateCommand(args: argparse.Namespace) -> None:
         assert isinstance(sp, AliasSearchPath)  # For mypy
         exprs[section] = exprs[sp.alias_of]
 
-    command = [
-        'nix-env',
-        '--profile',
-        args.profile,
-        '--show-trace',
-        '--file',
-        '<nix/unpack-channel.nix>',
-        '--install',
-        '--remove-all',
-    ] + search_paths + ['--from-expression'] + [
-        exprs[name] % name for name in sorted(exprs.keys())]
-    if args.dry_run:
-        print(' '.join(map(shlex.quote, command)))
-    else:
-        v.status('Installing channels with nix-env')
-        process = subprocess.run(command)
-        v.result(process.returncode == 0)
+    with tempfile.NamedTemporaryFile() as unpack_channel_nix:
+        unpack_channel_nix.write(b'''
+            { name, channelName, src, }:
+            derivation {
+              inherit name channelName src;
+              builder = "builtin:unpack-channel";
+              system = "builtin";
+              preferLocalBuild = true;
+            }
+            ''')
+        unpack_channel_nix.flush()
+
+        command = [
+            'nix-env',
+            '--profile',
+            args.profile,
+            '--show-trace',
+            '--file',
+            unpack_channel_nix.name,
+            '--install',
+            '--remove-all',
+        ] + search_paths + ['--from-expression'] + [
+            exprs[name] % name for name in sorted(exprs.keys())]
+        if args.dry_run:
+            print(' '.join(map(shlex.quote, command)))
+        else:
+            v.status('Installing channels with nix-env')
+            process = subprocess.run(command)
+            v.result(process.returncode == 0)
 
 
 def main() -> None: