Mercurial > hg
view tests/test-mq-qpush-exact.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 | aa9385f983fa |
children | f1eaf03dd608 |
line wrap: on
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH make a test repository that looks like this: o 2:28bc7b1afd6a | | @ 1:d7fe2034f71b |/ o 0/62ecad8b70e5 $ hg init r0 $ cd r0 $ touch f0 $ hg ci -m0 -Aq $ touch f1 $ hg ci -m1 -Aq $ hg update 0 -q $ touch f2 $ hg ci -m2 -Aq $ hg update 1 -q make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1 $ echo cp0 >> fp0 $ hg add fp0 $ hg ci -m p0 -d "0 0" $ hg export -r. > p0 $ hg strip -qn . $ hg qimport p0 adding p0 to series file $ hg qpush applying p0 now at: p0 $ echo cp1 >> fp1 $ hg add fp1 $ hg qnew p1 -d "0 0" $ hg qpop -aq patch queue now empty qpush --exact when at the parent $ hg update 1 -q $ hg qpush -e applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg qpush -e p0 applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg qpush -e p1 applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact when at another rev $ hg update 0 -q $ hg qpush -e 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -e p0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -e p1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -ea 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact while crossing branches $ hg update 2 -q $ hg qpush -e 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -e p0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -e p1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -ea 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact --force with changes to an unpatched file $ hg update 1 -q $ echo c0 >> f0 $ hg qpush -e abort: local changes found [255] $ hg qpush -ef applying p0 now at: p0 $ cat f0 c0 $ rm f0 $ touch f0 $ hg qpop -aq patch queue now empty $ hg update 1 -q $ echo c0 >> f0 $ hg qpush -e p1 abort: local changes found [255] $ hg qpush -e p1 -f applying p0 applying p1 now at: p1 $ cat f0 c0 $ rm f0 $ touch f0 $ hg qpop -aq patch queue now empty qpush --exact --force with changes to a patched file $ hg update 1 -q $ echo cp0-bad >> fp0 $ hg add fp0 $ hg qpush -e abort: local changes found [255] $ hg qpush -ef applying p0 file fp0 already exists 1 out of 1 hunks FAILED -- saving rejects to file fp0.rej patch failed, unable to continue (try -v) patch failed, rejects left in working dir errors during apply, please fix and refresh p0 [2] $ cat fp0 cp0-bad $ cat fp0.rej --- fp0 +++ fp0 @@ -0,0 +1,1 @@ +cp0 $ hg qpop -aqf patch queue now empty $ rm fp0 $ rm fp0.rej $ hg update 1 -q $ echo cp1-bad >> fp1 $ hg add fp1 $ hg qpush -e p1 abort: local changes found [255] $ hg qpush -e p1 -f applying p0 applying p1 file fp1 already exists 1 out of 1 hunks FAILED -- saving rejects to file fp1.rej patch failed, unable to continue (try -v) patch failed, rejects left in working dir errors during apply, please fix and refresh p1 [2] $ cat fp1 cp1-bad $ cat fp1.rej --- fp1 +++ fp1 @@ -0,0 +1,1 @@ +cp1 $ hg qpop -aqf patch queue now empty $ hg forget fp1 $ rm fp1 $ rm fp1.rej qpush --exact when already at a patch $ hg update 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg qpush -e p0 applying p0 now at: p0 $ hg qpush -e p1 abort: cannot push --exact with applied patches [255] $ hg qpop -aq patch queue now empty qpush --exact --move should fail $ hg qpush -e --move p1 abort: cannot use --exact and --move together [255] qpush --exact a patch without a parent recorded $ hg qpush -q now at: p0 $ grep -v '# Parent' .hg/patches/p0 > p0.new $ mv p0.new .hg/patches/p0 $ hg qpop -aq patch queue now empty $ hg qpush -e abort: p0 does not have a parent recorded [255] $ hg qpush -e p0 abort: p0 does not have a parent recorded [255] $ hg qpush -e p1 abort: p0 does not have a parent recorded [255] $ hg qpush -ea abort: p0 does not have a parent recorded [255] $ cd ..