Mercurial > hg
view tests/test-unionrepo.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 | 198b003a2263 |
children | bf86e3e87123 |
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Test unionrepo functionality Create one repository $ hg init repo1 $ cd repo1 $ touch repo1-0 $ echo repo1-0 > f $ hg ci -Aqmrepo1-0 $ touch repo1-1 $ echo repo1-1 >> f $ hg ci -Aqmrepo1-1 $ touch repo1-2 $ echo repo1-2 >> f $ hg ci -Aqmrepo1-2 $ hg log --template '{rev}:{node|short} {desc|firstline}\n' 2:68c0685446a3 repo1-2 1:8a58db72e69d repo1-1 0:f093fec0529b repo1-0 $ tip1=`hg id -q` $ cd .. - and a clone with a not-completely-trivial history $ hg clone -q repo1 --rev 0 repo2 $ cd repo2 $ touch repo2-1 $ sed '1i\ > repo2-1 at top > ' f > f.tmp $ mv f.tmp f $ hg ci -Aqmrepo2-1 $ touch repo2-2 $ hg pull -q ../repo1 -r 1 $ hg merge -q $ hg ci -Aqmrepo2-2-merge $ touch repo2-3 $ echo repo2-3 >> f $ hg ci -mrepo2-3 $ hg log --template '{rev}:{node|short} {desc|firstline}\n' 4:2f0d178c469c repo2-3 3:9e6fb3e0b9da repo2-2-merge 2:8a58db72e69d repo1-1 1:c337dba826e7 repo2-1 0:f093fec0529b repo1-0 $ cd .. revisions from repo2 appear as appended / pulled to repo1 $ hg -R union:repo1+repo2 log --template '{rev}:{node|short} {desc|firstline}\n' 5:2f0d178c469c repo2-3 4:9e6fb3e0b9da repo2-2-merge 3:c337dba826e7 repo2-1 2:68c0685446a3 repo1-2 1:8a58db72e69d repo1-1 0:f093fec0529b repo1-0 manifest can be retrieved for revisions in both repos $ hg -R union:repo1+repo2 mani -r $tip1 f repo1-0 repo1-1 repo1-2 $ hg -R union:repo1+repo2 mani -r 4 f repo1-0 repo1-1 repo2-1 repo2-2 files can be retrieved form both repos $ hg -R repo1 cat repo1/f -r2 repo1-0 repo1-1 repo1-2 $ hg -R union:repo1+repo2 cat -r$tip1 repo1/f repo1-0 repo1-1 repo1-2 $ hg -R union:repo1+repo2 cat -r4 $TESTTMP/repo1/f repo2-1 at top repo1-0 repo1-1 files can be compared across repos $ hg -R union:repo1+repo2 diff -r$tip1 -rtip diff -r 68c0685446a3 -r 2f0d178c469c f --- a/f Thu Jan 01 00:00:00 1970 +0000 +++ b/f Thu Jan 01 00:00:00 1970 +0000 @@ -1,3 +1,4 @@ +repo2-1 at top repo1-0 repo1-1 -repo1-2 +repo2-3 heads from both repos are found correctly $ hg -R union:repo1+repo2 heads --template '{rev}:{node|short} {desc|firstline}\n' 5:2f0d178c469c repo2-3 2:68c0685446a3 repo1-2 revsets works across repos $ hg -R union:repo1+repo2 id -r "ancestor($tip1, 5)" 8a58db72e69d annotate works - an indication that linkrevs works $ hg --cwd repo1 -Runion:../repo2 annotate $TESTTMP/repo1/f -r tip 3: repo2-1 at top 0: repo1-0 1: repo1-1 5: repo2-3 union repos can be cloned ... and clones works correctly $ hg clone -U union:repo1+repo2 repo3 requesting all changes adding changesets adding manifests adding file changes added 6 changesets with 11 changes to 6 files (+1 heads) $ hg -R repo3 paths default = union:repo1+repo2 $ hg -R repo3 verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 6 files, 6 changesets, 11 total revisions $ hg -R repo3 heads --template '{rev}:{node|short} {desc|firstline}\n' 5:2f0d178c469c repo2-3 2:68c0685446a3 repo1-2 $ hg -R repo3 log --template '{rev}:{node|short} {desc|firstline}\n' 5:2f0d178c469c repo2-3 4:9e6fb3e0b9da repo2-2-merge 3:c337dba826e7 repo2-1 2:68c0685446a3 repo1-2 1:8a58db72e69d repo1-1 0:f093fec0529b repo1-0