Description
Bug report
This is a regression between Python 3.11.0 and 3.11.1. Since 46a3cf4 (88297e2, #98692), py.exe no longer observes the “custom commands” mapping under [commands] in py.ini defining additional “virtual commands” (unless the virtual command starts with the same prefix as one of the four predefined virtual commands), but directly tries to launch the virtual command as an executable.
Steps to reproduce:
%WINDIR%\py.ini:
[commands]
/opt/something/bin/my-python2=C:\something\python27\python.exetest.py:
#!/opt/something/bin/my-python2
import sys
print('hello from', sys.executable)%WINDIR%\py.exe test.py
Expected result (and actual up to 3.11.0):
('hello from', 'C:\\something\\python27\\python.exe')
Actual result:
Unable to create process using 'C:\opt\something\bin\my-python2 test.py': The system cannot find the file specified.
I seem to be able to fix this as follows, which satisfies the existing tests, however this code is such a complex tangle of special cases that I have no idea whether it is the right thing to do. (The idea is that the loop over shebangTemplates should always find exactly one match, which was previously (before the regression) ensured by the empty template, so that _findCommand() is always called. Checking for tmpl != &shebangTemplates[0] is needed to satisfy test_recursive_search_path, however it might exclude too much – maybe searchPath() should instead report explicitly that it skipped a recursive call.)
diff --git a/PC/launcher2.c b/PC/launcher2.c
index 9b3db04aa4..ad313c10f3 100644
--- a/PC/launcher2.c
+++ b/PC/launcher2.c
@@ -1001,19 +1001,13 @@ checkShebang(SearchInfo *search)
L"/usr/bin/env ",
L"/usr/bin/",
L"/usr/local/bin/",
- L"python",
+ L"",
NULL
};
for (const wchar_t **tmpl = shebangTemplates; *tmpl; ++tmpl) {
if (_shebangStartsWith(shebang, shebangLength, *tmpl, &command)) {
commandLength = 0;
- // Normally "python" is the start of the command, but we also need it
- // as a shebang prefix for back-compat. We move the command marker back
- // if we match on that one.
- if (0 == wcscmp(*tmpl, L"python")) {
- command -= 6;
- }
while (command[commandLength] && !isspace(command[commandLength])) {
commandLength += 1;
}
@@ -1052,18 +1046,20 @@ checkShebang(SearchInfo *search)
debug(L"# Treating shebang command '%.*s' as 'py'\n",
commandLength, command);
}
+ } else if (tmpl != &shebangTemplates[0]) {
+ // Unrecognised commands are joined to the script's directory and treated
+ // as the executable path
+ return _useShebangAsExecutable(search, shebang, shebangLength);
} else {
debug(L"# Found shebang command but could not execute it: %.*s\n",
commandLength, command);
}
// search is done by this point
- return 0;
+ break;
}
}
- // Unrecognised commands are joined to the script's directory and treated
- // as the executable path
- return _useShebangAsExecutable(search, shebang, shebangLength);
+ return 0;
}
Your environment
- CPython versions tested on: 3.9, 3.10, 3.11.0 (good), 3.11.1 (bad)
- Operating system and architecture: Windows 10 Pro 10.0.19043.2006 AMD64
Linked PRs
- gh-100247: Fix py.exe launcher not using entire shebang command for finding custom commands #100944
- [3.11] gh-100247: Fix py.exe launcher not using entire shebang command for finding custom commands (GH-100944) #101012
- gh-100247: Improve documentation for custom shebang commands in py.exe launcher #101083
- [3.11] gh-100247: Improve documentation for custom shebang commands in py.exe launcher (GH-101083) #101084