Mercurial > hg
view tests/test-import-merge.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 | 3a3731a60354 |
children | f3200bf460a8 0c838e7459a5 |
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH $ tipparents() { > hg parents --template "{rev}:{node|short} {desc|firstline}\n" -r tip > } Test import and merge diffs $ hg init repo $ cd repo $ echo a > a $ hg ci -Am adda adding a $ echo a >> a $ hg ci -m changea $ echo c > c $ hg ci -Am addc adding c $ hg up 0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo b > b $ hg ci -Am addb adding b created new head $ hg up 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge 3 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m merge $ hg export . > ../merge.diff $ cd .. $ hg clone -r2 repo repo2 adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 2 files updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd repo2 $ hg pull -r3 ../repo pulling from ../repo searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) Test without --exact and diff.p1 == workingdir.p1 $ hg up 1 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg import ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test without --exact and diff.p1 != workingdir.p1 $ hg up 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import ../merge.diff applying ../merge.diff $ tipparents 2:890ecaa90481 addc $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test with --exact $ hg import --exact ../merge.diff applying ../merge.diff 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test with --bypass and diff.p1 == workingdir.p1 $ hg up 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import --bypass ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip Test with --bypass and diff.p1 != workingdir.p1 $ hg up 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import --bypass ../merge.diff applying ../merge.diff $ tipparents 2:890ecaa90481 addc $ hg strip --no-backup tip Test with --bypass and --exact $ hg import --bypass --exact ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip $ cd .. Test that --exact on a bad header doesn't corrupt the repo (issue3616) $ hg init repo3 $ cd repo3 $ echo a>a $ hg ci -Aqm0 $ echo a>>a $ hg ci -m1 $ echo a>>a $ hg ci -m2 $ echo a>a $ echo b>>a $ echo a>>a $ hg ci -m3 $ hg export 2 | head -7 > ../a.patch $ hg export tip > out >>> apatch = open("../a.patch", "ab") >>> apatch.write("".join(open("out").readlines()[7:])) $ cd .. $ hg clone -qr0 repo3 repo3-clone $ cd repo3-clone $ hg pull -qr1 ../repo3 $ hg import --exact ../a.patch applying ../a.patch 1 files updated, 0 files merged, 0 files removed, 0 files unresolved patching file a Hunk #1 succeeded at 1 with fuzz 1 (offset -1 lines). transaction abort! rollback completed abort: patch is damaged or loses information [255] $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 2 changesets, 2 total revisions