From b9125325d99aa555ef303ed6729f6e36561483d1 Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <campbell+pypa-installer@mumble.net>
Date: Wed, 15 Jan 2025 21:40:53 +0000
Subject: [PATCH] Implement `--executable' option (#257)

---
 src/installer/__main__.py |  9 ++++++++-
 tests/test_main.py        | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/installer/__main__.py b/src/installer/__main__.py
index 00c7df5..b2dbea5 100644
--- a/src/installer/__main__.py
+++ b/src/installer/__main__.py
@@ -31,6 +31,13 @@ def _get_main_parser() -> argparse.ArgumentParser:
         type=str,
         help="override prefix to install packages to",
     )
+    parser.add_argument(
+        "--executable",
+        metavar="path",
+        default=sys.executable,
+        type=str,
+        help="#! executable to install scripts with (default=sys.executable)",
+    )
     parser.add_argument(
         "--compile-bytecode",
         action="append",
@@ -103,7 +110,7 @@ def _main(cli_args: Sequence[str], program: Optional[str] = None) -> None:
                 source.validate_record(validate_contents=args.validate_record == "all")
             destination = SchemeDictionaryDestination(
                 scheme_dict=_get_scheme_dict(source.distribution, prefix=args.prefix),
-                interpreter=sys.executable,
+                interpreter=args.executable,
                 script_kind=get_launcher_kind(),
                 bytecode_optimization_levels=bytecode_levels,
                 destdir=args.destdir,
diff --git a/tests/test_main.py b/tests/test_main.py
index cb09b3d..3200819 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -74,6 +74,28 @@ def test_main_prefix(fancy_wheel, tmp_path):
     }
 
 
+def test_main_executable(fancy_wheel, tmp_path):
+    destdir = tmp_path / "dest"
+
+    main(
+        [
+            str(fancy_wheel),
+            "-d",
+            str(destdir),
+            "--executable",
+            "/monty/python3.x",
+        ],
+        "python -m installer",
+    )
+
+    installed_scripts = destdir.rglob("bin/*")
+
+    for f in installed_scripts:
+        with f.open("rb") as fp:
+            shebang = fp.readline()
+            assert shebang == b"#!/monty/python3.x\n"
+
+
 def test_main_no_pyc(fancy_wheel, tmp_path):
     destdir = tmp_path / "dest"