diff --git a/scripts/build/icon_environment.py b/scripts/build/icon_environment.py
new file mode 100644
index 0000000000..f7f2e76a30
--- /dev/null
+++ b/scripts/build/icon_environment.py
@@ -0,0 +1,36 @@
+"""Prepare the locked icon-only environment through PM, then run the generator."""
+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+import subprocess
+import sys
+from tempfile import TemporaryDirectory
+
+# The Node wrapper can run this file from a separately prepared source tree.
+ROOT = Path(__file__).resolve().parents[2]
+sys.path.insert(0, str(ROOT))
+
+import pm
+
+
+def main(argv: list[str] | None = None) -> int:
+    argv = list(sys.argv[1:] if argv is None else argv)
+    parser = argparse.ArgumentParser(add_help=False, allow_abbrev=False)
+    parser.add_argument("--source", type=Path, default=ROOT)
+    args, _ = parser.parse_known_args(argv)
+    source = args.source.resolve()
+    with TemporaryDirectory(prefix="hermes-icon-build-") as temporary:
+        python = pm.build_environment(
+            source=source, out=Path(temporary) / "venv",
+            groups=["icon-build"], only_groups=True, explicit=True,
+            cache=source / ".cache/icon-build",
+        )
+        return subprocess.run(
+            [str(python), "-I", str(ROOT / "scripts/generate_icons.py"), *argv],
+            cwd=source,
+        ).returncode
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/scripts/generate-icons.mjs b/scripts/generate-icons.mjs
index 8029a890e3..2980f5ffe3 100644
--- a/scripts/generate-icons.mjs
+++ b/scripts/generate-icons.mjs
@@ -29,16 +29,13 @@ export function generateIcons(args = [], { root = repoRoot, run = spawnSync, env
   // Parent payload paths must not shadow the isolated build dependencies.
   delete childEnv.PYTHONPATH
   delete childEnv.PYTHONHOME
-  const result = run('uv', [
-    'run', '--isolated', '--locked', '--only-group', 'icon-build',
-    // PM copies its wheel cache into payloads. Keep build wheels outside it.
-    '--cache-dir', path.join(source, '.cache', 'icon-build'),
-    'python', path.join(root, 'scripts', 'generate_icons.py'), '--source', source, '--out', out,
+  const result = run(env.HERMES_PYTHON || 'python', [
+    path.join(root, 'scripts', 'build', 'icon_environment.py'), '--source', source, '--out', out,
     ...(values.check ? ['--check'] : [])
   ], { cwd: source, stdio: 'inherit', windowsHide: true, env: childEnv })
   if (result.error) {
     console.error('[generate-icons] failed to launch icon generator:', result.error.message)
-    console.error('[generate-icons] uv is required to run the isolated icon-build group')
+    console.error('[generate-icons] a prepared Python (HERMES_PYTHON or PATH) is required to run the PM build driver')
     return 1
   }
   return result.status ?? 1
diff --git a/tests-js/generate-icons.test.mjs b/tests-js/generate-icons.test.mjs
index 59d796a13e..5a1ac7539d 100644
--- a/tests-js/generate-icons.test.mjs
+++ b/tests-js/generate-icons.test.mjs
@@ -1,17 +1,17 @@
+import { spawnSync } from 'node:child_process'
 import path from 'node:path'
+import { fileURLToPath } from 'node:url'
 import { expect, test, vi } from 'vitest'
 import { generateIcons } from '../scripts/generate-icons.mjs'
 
-test('icon builds use only the locked build group outside every application venv', () => {
+test('icon builds delegate environment preparation to PM using the prepared Python', () => {
   const run = vi.fn(() => ({ status: 0 }))
   const root = path.resolve('icon-build-fixture')
-  const env = { PATH: 'tools', UV_PYTHON: 'pm-locked-python', VIRTUAL_ENV: 'runtime-venv', PYTHONPATH: 'payload-libraries', PYTHONHOME: 'payload-python' }
+  const env = { PATH: 'tools', HERMES_PYTHON: 'prepared-python', VIRTUAL_ENV: 'runtime-venv', PYTHONPATH: 'payload-libraries', PYTHONHOME: 'payload-python' }
   expect(generateIcons(['--check'], { root, run, env })).toBe(0)
-  expect(run).toHaveBeenCalledExactlyOnceWith('uv', [
-    'run', '--isolated', '--locked', '--only-group', 'icon-build',
-    '--cache-dir', path.join(root, '.cache', 'icon-build'),
-    'python', path.join(root, 'scripts', 'generate_icons.py'), '--source', root, '--out', root, '--check'
-  ], { cwd: root, stdio: 'inherit', windowsHide: true, env: { PATH: 'tools', UV_PYTHON: env.UV_PYTHON, VIRTUAL_ENV: 'runtime-venv' } })
+  expect(run).toHaveBeenCalledExactlyOnceWith(env.HERMES_PYTHON, [
+    path.join(root, 'scripts', 'build', 'icon_environment.py'), '--source', root, '--out', root, '--check'
+  ], { cwd: root, stdio: 'inherit', windowsHide: true, env: { PATH: 'tools', HERMES_PYTHON: env.HERMES_PYTHON, VIRTUAL_ENV: 'runtime-venv' } })
   expect(env.PYTHONPATH).toBe('payload-libraries')
 })
 
@@ -19,19 +19,57 @@ test('icon preparation passes explicit source and independent output roots', ()
   const run = vi.fn(() => ({ status: 0 }))
   const source = path.resolve('source with spaces')
   const out = path.resolve('icon outputs')
-  expect(generateIcons(['--source', source, '--out', out], { run })).toBe(0)
-  const [, args, options] = run.mock.calls[0]
+  expect(generateIcons(['--source', source, '--out', out], { run, env: {} })).toBe(0)
+  const [python, args, options] = run.mock.calls[0]
+  expect(python).toBe('python')
   expect(args.slice(-4)).toEqual(['--source', source, '--out', out])
   expect(options.cwd).toBe(source)
 })
 
+test('the PM driver owns a temporary group-only environment and preserves generator argv and status', () => {
+  const result = spawnSync(process.env.HERMES_PYTHON || 'python', ['-c', `
+from pathlib import Path
+import subprocess
+import sys
+from tempfile import TemporaryDirectory
+from unittest.mock import patch
+from scripts.build import icon_environment
+
+with TemporaryDirectory() as directory:
+    source = Path(directory) / 'source with spaces'
+    source.mkdir()
+    argv = ['--source', str(source), '--out', str(Path(directory) / 'icon outputs'), '--check']
+    outputs = []
+    def build(**options):
+        output = options.pop('out')
+        assert output.parent.is_dir() and not output.exists()
+        assert output.name == 'venv'
+        assert options == dict(source=source, groups=['icon-build'], only_groups=True,
+                               explicit=True, cache=source / '.cache/icon-build')
+        outputs.append(output)
+        return Path(sys.executable)
+    def generate(command, **options):
+        assert outputs[0].parent.is_dir()
+        assert command == [sys.executable, '-I', str(Path(icon_environment.__file__).resolve().parents[1] / 'generate_icons.py'), *argv]
+        assert options == dict(cwd=source)
+        return subprocess.CompletedProcess(command, 7)
+    with patch.object(icon_environment.pm, 'build_environment', side_effect=build) as prepare, patch.object(icon_environment.subprocess, 'run', side_effect=generate) as run:
+        assert icon_environment.main(argv) == 7
+        prepare.assert_called_once()
+        run.assert_called_once()
+    assert not outputs[0].parent.exists()
+`], { cwd: fileURLToPath(new URL('..', import.meta.url)), encoding: 'utf8' })
+  expect(result.error).toBeUndefined()
+  expect(result.status, result.stderr).toBe(0)
+})
+
 test('failed icon processes cannot report a successful build', () => {
   expect(generateIcons([], { run: () => ({ status: 7 }), env: {} })).toBe(7)
   expect(generateIcons([], { run: () => ({ status: null, signal: 'SIGTERM' }), env: {} })).toBe(1)
   const error = vi.spyOn(console, 'error').mockImplementation(() => {})
   try {
-    expect(generateIcons([], { run: () => ({ error: new Error('uv missing') }), env: {} })).toBe(1)
-    expect(error).toHaveBeenCalledWith(expect.stringContaining('failed to launch'), 'uv missing')
+    expect(generateIcons([], { run: () => ({ error: new Error('prepared Python missing') }), env: {} })).toBe(1)
+    expect(error).toHaveBeenCalledWith(expect.stringContaining('failed to launch'), 'prepared Python missing')
   } finally {
     error.mockRestore()
   }