Mercurial > hg
view tests/test-identify.t @ 20742:3681de20b0a7
parsers: fail fast if Python has wrong minor version (issue4110)
This change causes an informative ImportError to be raised when importing
the parsers extension module if the minor version of the currently-running
Python interpreter doesn't match that of the Python used when compiling
the extension module.
This change also exposes a parsers.versionerrortext constant in the
C implementation of the module. Its presence can be used to determine
whether this behavior is present in a version of the module. The value
of the constant is the leading text of the ImportError raised and is set
to "Python minor version mismatch".
Here is an example of what the new error looks like:
Traceback (most recent call last):
File "test.py", line 1, in <module>
import mercurial.parsers
ImportError: Python minor version mismatch: The Mercurial extension
modules were compiled with Python 2.7.6, but Mercurial is currently using
Python with sys.hexversion=33883888: Python 2.5.6
(r256:88840, Nov 18 2012, 05:37:10)
[GCC 4.2.1 Compatible Apple Clang 4.1 ((tags/Apple/clang-421.11.66))]
at: /opt/local/Library/Frameworks/Python.framework/Versions/2.5/Resources/
Python.app/Contents/MacOS/Python
The reason for raising an error in this scenario is that Python's C API
is known not to be compatible from minor version to minor version, even
if sys.api_version is the same. See for example this Python bug report
about incompatibilities between 2.5 and 2.6+:
http://bugs.python.org/issue8118
These incompatibilities can cause Mercurial to break in mysterious,
unforeseen ways. For example, when Mercurial compiled with Python 2.7 was
run with 2.5, the following crash occurred when running "hg status":
http://bz.selenic.com/show_bug.cgi?id=4110
After this crash was fixed, running with Python 2.5 no longer crashes, but
the following puzzling behavior still occurs:
$ hg status
...
File ".../mercurial/changelog.py", line 123, in __init__
revlog.revlog.__init__(self, opener, "00changelog.i")
File ".../mercurial/revlog.py", line 251, in __init__
d = self._io.parseindex(i, self._inline)
File ".../mercurial/revlog.py", line 158, in parseindex
index, cache = parsers.parse_index2(data, inline)
TypeError: data is not a string
which can be reproduced more simply with:
import mercurial.parsers as parsers
parsers.parse_index2("", True)
Both the crash and the TypeError occurred because the Python C API's
PyString_Check() returns the wrong value when the C header files from
Python 2.7 are run with Python 2.5. This is an example of an
incompatibility of the sort mentioned in the Python bug report above.
Failing fast with an informative error message results in a better user
experience in cases like the above. The information in the ImportError
also simplifies troubleshooting for those on Mercurial mailing lists, the
bug tracker, etc.
This patch only adds the version check to parsers.c, which is sufficient
to affect command-line commands like "hg status" and "hg summary".
An idea for a future improvement is to move the version-checking C code
to a more central location, and have it run when importing all
Mercurial extension modules and not just parsers.c.
author | Chris Jerdonek <chris.jerdonek@gmail.com> |
---|---|
date | Wed, 04 Dec 2013 20:38:27 -0800 |
parents | b93791e0de25 |
children | f8e531a3a77c |
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$ "$TESTDIR/hghave" serve || exit 80 #if no-outer-repo no repo $ hg id abort: there is no Mercurial repository here (.hg not found) [255] #endif create repo $ hg init test $ cd test $ echo a > a $ hg ci -Ama adding a basic id usage $ hg id cb9a9f314b8b tip $ hg id --debug cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b tip $ hg id -q cb9a9f314b8b $ hg id -v cb9a9f314b8b tip with options $ hg id -r. cb9a9f314b8b tip $ hg id -n 0 $ hg id -t tip $ hg id -b default $ hg id -i cb9a9f314b8b $ hg id -n -t -b -i cb9a9f314b8b 0 default tip with modifications $ echo b > a $ hg id -n -t -b -i cb9a9f314b8b+ 0+ default tip other local repo $ cd .. $ hg -R test id cb9a9f314b8b+ tip #if no-outer-repo $ hg id test cb9a9f314b8b+ tip #endif with remote http repo $ cd test $ hg serve -p $HGPORT1 -d --pid-file=hg.pid $ cat hg.pid >> $DAEMON_PIDS $ hg id http://localhost:$HGPORT1/ cb9a9f314b8b remote with rev number? $ hg id -n http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [255] remote with tags? $ hg id -t http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [255] remote with branch? $ hg id -b http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [255] test bookmark support $ hg bookmark Y $ hg bookmark Z $ hg bookmarks Y 0:cb9a9f314b8b * Z 0:cb9a9f314b8b $ hg id cb9a9f314b8b+ tip Y/Z $ hg id --bookmarks Y Z test remote identify with bookmarks $ hg id http://localhost:$HGPORT1/ cb9a9f314b8b Y/Z $ hg id --bookmarks http://localhost:$HGPORT1/ Y Z $ hg id -r . http://localhost:$HGPORT1/ cb9a9f314b8b Y/Z $ hg id --bookmarks -r . http://localhost:$HGPORT1/ Y Z Make sure we do not obscure unknown requires file entries (issue2649) $ echo fake >> .hg/requires $ hg id abort: unknown repository format: requires features 'fake' (upgrade Mercurial)! (see http://mercurial.selenic.com/wiki/MissingRequirement for details) [255] $ cd .. #if no-outer-repo $ hg id test abort: unknown repository format: requires features 'fake' (upgrade Mercurial)! (see http://mercurial.selenic.com/wiki/MissingRequirement for details) [255] #endif