cherry_picker now can only be run from CPython repo

cherry_picker/cherry_picker/cherry_picker.py

@@ -271,11 +271,10 @@ def cherry_pick_cli(dry_run, pr_remote, abort, status, push,
                     commit_sha1, branches):
 
     click.echo("\U0001F40D \U0001F352 \u26CF")
-    current_dir = os.getcwd()
-    pyconfig_path = os.path.join(current_dir, 'pyconfig.h.in')
 
-    if not os.path.exists(pyconfig_path):
-        os.chdir(os.path.join(current_dir, 'cpython'))
+    if not is_cpython_repo():
+        click.echo("You're not inside a CPython repo right now! 🙅")
+        sys.exit(-1)
 
     if dry_run:
         click.echo("Dry run requested, listing expected command sequence")
@@ -320,5 +319,14 @@ def get_full_sha_from_short(short_sha):
     return full_sha
 
 
+def is_cpython_repo():
+    cmd = "git log -r 7f777ed95a19224294949e1b4ce56bbffcb1fe9f"
+    try:
+        subprocess.check_output(cmd.split(), stderr=subprocess.STDOUT)
+    except subprocess.SubprocessError:
+        return False
+    return True
+
+
 if __name__ == '__main__':
     cherry_pick_cli()

cherry_picker/cherry_picker/test.py

@@ -3,7 +3,7 @@
 import pytest
 
 from .cherry_picker import get_base_branch, get_current_branch, \
-    get_full_sha_from_short, CherryPicker
+    get_full_sha_from_short, is_cpython_repo, CherryPicker
 
 
 def test_get_base_branch():
@@ -97,3 +97,18 @@ def test_get_updated_commit_message(subprocess_check_output, os_path_exists):
                       branches)
     assert cp.get_commit_message('22a594a0047d7706537ff2ac676cdc0f1dcb329c') \
            == 'bpo-123: Fix Spam Module (GH-113)'
+
+@mock.patch('subprocess.check_output')
+def test_is_cpython_repo(subprocess_check_output):
+    subprocess_check_output.return_value = """commit 7f777ed95a19224294949e1b4ce56bbffcb1fe9f
+Author: Guido van Rossum <[email protected]>
+Date:   Thu Aug 9 14:25:15 1990 +0000
+
+    Initial revision
+
+"""
+    assert is_cpython_repo() == True
+
+def test_is_not_cpython_repo():
+    assert is_cpython_repo() == False
+