-
-
Notifications
You must be signed in to change notification settings - Fork 30k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
sysconfig generation uses some env variables multiple times #61879
Comments
When compiling Python 3.3.1, I noticed that some variables like LDFLAGS or CFLAGS in sysconfig have some flags multiple times. (Which BTW breaks distutils.tests.{test_sysconfig_compiler_vars,test_sysconfig_module}) This is caused by interpretation of Makefile in sysconfig._parse_makefile(), which seems to evaluate the variables in Makefile - but some variables in Makefile are formed by expanding env variables multiple times, e.g.: Thanks. |
There definitely are configurations where some values do get duplicated in CFLAGS and LDFLAGS. In my experience this is generally harmless for builds but, as you point out, it can break tests that expect particular values. It would be nice to clean this up. |
I'm attaching a patch that I'm currently using to solve this. It works, but it's a bit aggressive - in the sense that it only adds a string to the sysconfig variable iff this string is not a substring of current variable value. So it may corrupt some values, e.g. it wouldn't add "python" to variable if that variable already had "/usr/lib/python". But it seems to get all the values just fine for me. |
Another solution may be to make the test more relaxed and regard the value returned by sysconfig.get_config_var() as a _set_ of shell tokens, whose elements may occur more than once, e.g. def test_sysconfig_module(self):
import sysconfig as global_sysconfig
from shlex import split
self.assertEqual(
set(split(global_sysconfig.get_config_var('CFLAGS'))),
set(split(sysconfig.get_config_var('CFLAGS'))))
self.assertEqual(
set(split(global_sysconfig.get_config_var('LDFLAGS'))),
set(split(sysconfig.get_config_var('LDFLAGS')))) |
The patch doesn't look good to me. If the value contains "-lfoo-lbar $(name)" then substituting name="-lfoo" or name="-lbar" doesn't work. |
I don't think that the attached patch is correct. See attached install.diff: difference without/with 00178-dont-duplicate-flags-in-sysconfig.patch on Python installed in /usr/bin/python3. Example of bug: 'TESTRUNNER': 'LD_LIBRARY_PATH=/builddir/build/BUILD/Python-3.7.1/build/optimized '
- './python '
- '/builddir/build/BUILD/Python-3.7.1/Tools/scripts/run_tests.py',
+ './python /Tools/scripts/run_tests.py', The /Tools directory doesn't exist :-/
Technically, it's perfectly fine to pass the same flag multiple times. It's common to pass -O0 -Og to gcc for example: gcc uses the last -O option value (which overrides the previous ones). -- This patch is used in the python3 package of Fedora: Patch added by: commit 58f477b403222ea6c13d5d7358551b606cddc0f8
https://src.fedoraproject.org/rpms/python3/c/58f477b403222ea6c13d5d7358551b606cddc0f8?branch=master |
build.diff: Difference without/with the patch on Python build from source. Example:
This change is wrong: /Include directory doesn't exist. Another example:
I don't understand why "3.8" is removed from the path. |
The patch is wrong. I'm not sure when/how C flags are duplicated. Anyway, it seems like the issue is somehow outdated or even gone, so I close the issue. |
Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.
Show more details
GitHub fields:
bugs.python.org fields:
The text was updated successfully, but these errors were encountered: