PACKAGING-NOTES

Notes for packagers of Python3
==============================

0. Faster build turnaround
--------------------------

By default, python builds with profile-guided optimization. This needs
an additional run of the test suite and it is generally slow.
PGO build takes around 50 minutes.

For development, use "--without profileopt" option to disable PGO. This
shortens the build time to ~5 minutes including test suite.

1. import_failed.map
----------------------

This is a mechanism installed as part of python3-base, that places shim modules
on python's path (through a generated zzzz-import-failed-hooks.pth file, so that
it is imported as much at the end as makes sense; and an _import_failed subdir
of /usr/lib/pythonX.Y). Then when the user tries to import a module that is part
of a subpackage, the ImportError will contain a helpful message telling them
which missing subpackage to install.

This can sometimes cause problems on non-standard configurations, if the pth
gets included too early (for instance if you are using a script to include all
pths by hand in some strange order). Just something to look out for.
- Update to 3.10.17: - gh-131809: Update bundled libexpat to 2.7.1 - gh-131261: Upgrade to libexpat 2.7.0 - gh-105704: When using urllib.parse.urlsplit() and urllib.parse.urlparse() host parsing would not reject domain names containing square brackets ([ and ]). Square brackets are only valid for IPv6 and IPvFuture hosts according to RFC 3986 Section 3.2.2 (bsc#1236705, CVE-2025-0938, gh#python/cpython#105704). - gh-121284: Fix bug in the folding of rfc2047 encoded-words when flattening an email message using a modern email policy. Previously when an encoded-word was too long for a line, it would be decoded, split across lines, and re-encoded. But commas and other special characters in the original text could be left unencoded and unquoted. This could theoretically be used to spoof header lines using a carefully constructed encoded-word if the resulting rendered email was transmitted or re-parsed. - gh-80222: Fix bug in the folding of quoted strings when flattening an email message using a modern email policy. Previously when a quoted string was folded so that it spanned more than one line, the surrounding quotes and internal escapes would be omitted. This could theoretically be used to spoof header lines using a carefully constructed quoted string if the resulting rendered email was transmitted or re-parsed. - gh-119511: Fix a potential denial of service in the imaplib module. When connecting to a malicious server, it could cause an arbitrary amount of memory to be allocated. On many systems this is harmless as unused virtual memory is only OBS-URL: https://build.opensuse.org/package/show/devel:languages:python:Factory/python310?expand=0&rev=171 2025-04-11 08:15:51 +00:00			`Notes for packagers of Python3`
			`==============================`

			`0. Faster build turnaround`
			`--------------------------`

			`By default, python builds with profile-guided optimization. This needs`
			`an additional run of the test suite and it is generally slow.`
			`PGO build takes around 50 minutes.`

			`For development, use "--without profileopt" option to disable PGO. This`
			`shortens the build time to ~5 minutes including test suite.`

			`1. import_failed.map`
			`----------------------`

			`This is a mechanism installed as part of python3-base, that places shim modules`
			`on python's path (through a generated zzzz-import-failed-hooks.pth file, so that`
			`it is imported as much at the end as makes sense; and an _import_failed subdir`
			`of /usr/lib/pythonX.Y). Then when the user tries to import a module that is part`
			`of a subpackage, the ImportError will contain a helpful message telling them`
			`which missing subpackage to install.`

			`This can sometimes cause problems on non-standard configurations, if the pth`
			`gets included too early (for instance if you are using a script to include all`
			`pths by hand in some strange order). Just something to look out for.`