Mercurial > hg
view tests/test-minirst.py.out @ 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 | af9d9b778550 |
children | 58f8b29c37ff |
line wrap: on
line source
== paragraphs == 60 column format: ---------------------------------------------------------------------- This is some text in the first paragraph. A small indented paragraph. It is followed by some lines containing random whitespace. The third and final paragraph. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- This is some text in the first paragraph. A small indented paragraph. It is followed by some lines containing random whitespace. The third and final paragraph. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> This is some text in the first paragraph. </p> <p> A small indented paragraph. It is followed by some lines containing random whitespace. </p> <p> The third and final paragraph. </p> ---------------------------------------------------------------------- == definitions == 60 column format: ---------------------------------------------------------------------- A Term Definition. The indented lines make up the definition. Another Term Another definition. The final line in the definition determines the indentation, so this will be indented with four spaces. A Nested/Indented Term Definition. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- A Term Definition. The indented lines make up the definition. Another Term Another definition. The final line in the definition determines the indentation, so this will be indented with four spaces. A Nested/Indented Term Definition. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <dl> <dt>A Term <dd>Definition. The indented lines make up the definition. <dt>Another Term <dd>Another definition. The final line in the definition determines the indentation, so this will be indented with four spaces. <dt>A Nested/Indented Term <dd>Definition. </dl> ---------------------------------------------------------------------- == literals == 60 column format: ---------------------------------------------------------------------- The fully minimized form is the most convenient form: Hello literal world In the partially minimized form a paragraph simply ends with space-double-colon. //////////////////////////////////////// long un-wrapped line in a literal block \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ This literal block is started with '::', the so-called expanded form. The paragraph with '::' disappears in the final output. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- The fully minimized form is the most convenient form: Hello literal world In the partially minimized form a paragraph simply ends with space-double-colon. //////////////////////////////////////// long un-wrapped line in a literal block \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ This literal block is started with '::', the so-called expanded form. The paragraph with '::' disappears in the final output. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> The fully minimized form is the most convenient form: </p> <pre> Hello literal world </pre> <p> In the partially minimized form a paragraph simply ends with space-double-colon. </p> <pre> //////////////////////////////////////// long un-wrapped line in a literal block \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ </pre> <pre> This literal block is started with '::', the so-called expanded form. The paragraph with '::' disappears in the final output. </pre> ---------------------------------------------------------------------- == lists == 60 column format: ---------------------------------------------------------------------- - This is the first list item. Second paragraph in the first list item. - List items need not be separated by a blank line. - And will be rendered without one in any case. We can have indented lists: - This is an indented list item - Another indented list item: - A literal block in the middle of an indented list. (The above is not a list item since we are in the literal block.) Literal block with no indentation (apart from the two spaces added to all literal blocks). 1. This is an enumerated list (first item). 2. Continuing with the second item. (1) foo (2) bar 1) Another 2) List Line blocks are also a form of list: This is the first line. The line continues here. This is the second line. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- - This is the first list item. Second paragraph in the first list item. - List items need not be separated by a blank line. - And will be rendered without one in any case. We can have indented lists: - This is an indented list item - Another indented list item: - A literal block in the middle of an indented list. (The above is not a list item since we are in the literal block.) Literal block with no indentation (apart from the two spaces added to all literal blocks). 1. This is an enumerated list (first item). 2. Continuing with the second item. (1) foo (2) bar 1) Another 2) List Line blocks are also a form of list: This is the first line. The line continues here. This is the second line. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <ul> <li> This is the first list item. <p> Second paragraph in the first list item. </p> <li> List items need not be separated by a blank line. <li> And will be rendered without one in any case. </ul> <p> We can have indented lists: </p> <ul> <li> This is an indented list item <li> Another indented list item: <pre> - A literal block in the middle of an indented list. </pre> <pre> (The above is not a list item since we are in the literal block.) </pre> </ul> <pre> Literal block with no indentation (apart from the two spaces added to all literal blocks). </pre> <ol> <li> This is an enumerated list (first item). <li> Continuing with the second item. <li> foo <li> bar <li> Another <li> List </ol> <p> Line blocks are also a form of list: </p> <ol> <li> This is the first line. The line continues here. <li> This is the second line. </ol> ---------------------------------------------------------------------- == options == 60 column format: ---------------------------------------------------------------------- There is support for simple option lists, but only with long options: -X --exclude filter an option with a short and long option with an argument -I --include an option with both a short option and a long option --all Output all. --both Output both (this description is quite long). --long Output all day long. --par This option has two paragraphs in its description. This is the first. This is the second. Blank lines may be omitted between options (as above) or left in (as here). The next paragraph looks like an option list, but lacks the two-space marker after the option. It is treated as a normal paragraph: --foo bar baz ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- There is support for simple option lists, but only with long options: -X --exclude filter an option with a short and long option with an argumen t -I --include an option with both a short option and a long option --all Output all. --both Output both (this d escript ion is quite long). --long Output all day long. --par This option has two paragra phs in its des criptio n. This is the first. This is the second. Blank lines may be omitted between options (as above) or left in (as here). The next paragraph looks like an option list, but lacks the two-space marker after the option. It is treated as a normal paragraph: --foo bar baz ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> There is support for simple option lists, but only with long options: </p> <dl> <dt>-X --exclude filter <dd>an option with a short and long option with an argument <dt>-I --include <dd>an option with both a short option and a long option <dt> --all <dd>Output all. <dt> --both <dd>Output both (this description is quite long). <dt> --long <dd>Output all day long. <dt> --par <dd>This option has two paragraphs in its description. This is the first. <p> This is the second. Blank lines may be omitted between options (as above) or left in (as here). </p> </dl> <p> The next paragraph looks like an option list, but lacks the two-space marker after the option. It is treated as a normal paragraph: </p> <p> --foo bar baz </p> ---------------------------------------------------------------------- == fields == 60 column format: ---------------------------------------------------------------------- a First item. ab Second item. Indentation and wrapping is handled automatically. Next list: small The larger key below triggers full indentation here. much too large This key is big enough to get its own line. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- a First item. ab Second item. Indentation and wrapping is handled automatically. Next list: small The larger key below triggers full indentation here. much too large This key is big enough to get its own line. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <dl> <dt>a <dd>First item. <dt>ab <dd>Second item. Indentation and wrapping is handled automatically. </dl> <p> Next list: </p> <dl> <dt>small <dd>The larger key below triggers full indentation here. <dt>much too large <dd>This key is big enough to get its own line. </dl> ---------------------------------------------------------------------- == containers (normal) == 60 column format: ---------------------------------------------------------------------- Normal output. ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Normal output. ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Normal output. </p> ---------------------------------------------------------------------- == containers (verbose) == 60 column format: ---------------------------------------------------------------------- Normal output. Verbose output. ---------------------------------------------------------------------- ['debug', 'debug'] ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Normal output. Verbose output. ---------------------------------------------------------------------- ['debug', 'debug'] ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Normal output. </p> <p> Verbose output. </p> ---------------------------------------------------------------------- ['debug', 'debug'] ---------------------------------------------------------------------- == containers (debug) == 60 column format: ---------------------------------------------------------------------- Normal output. Initial debug output. ---------------------------------------------------------------------- ['verbose'] ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Normal output. Initial debug output. ---------------------------------------------------------------------- ['verbose'] ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Normal output. </p> <p> Initial debug output. </p> ---------------------------------------------------------------------- ['verbose'] ---------------------------------------------------------------------- == containers (verbose debug) == 60 column format: ---------------------------------------------------------------------- Normal output. Initial debug output. Verbose output. Debug output. ---------------------------------------------------------------------- [] ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Normal output. Initial debug output. Verbose output. Debug output. ---------------------------------------------------------------------- [] ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Normal output. </p> <p> Initial debug output. </p> <p> Verbose output. </p> <p> Debug output. </p> ---------------------------------------------------------------------- [] ---------------------------------------------------------------------- == roles == 60 column format: ---------------------------------------------------------------------- Please see "hg add". ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Please see "hg add". ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Please see "hg add". </p> ---------------------------------------------------------------------- == sections == 60 column format: ---------------------------------------------------------------------- Title ===== Section ------- Subsection '''''''''' Markup: "foo" and "hg help" --------------------------- ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Title ===== Section ------- Subsection '''''''''' Markup: "foo" and "hg help" --------------------------- ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <h1>Title</h1> <h2>Section</h2> <h3>Subsection</h3> <h2>Markup: "foo" and "hg help"</h2> ---------------------------------------------------------------------- == admonitions == 60 column format: ---------------------------------------------------------------------- Note: This is a note - Bullet 1 - Bullet 2 Warning! This is a warning Second input line of warning !Danger! This is danger ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Note: This is a note - Bullet 1 - Bullet 2 Warning! This is a warning Second input line of warning !Danger! This is danger ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> <b>Note:</b> </p> <p> This is a note </p> <ul> <li> Bullet 1 <li> Bullet 2 </ul> <p> <b>Warning!</b> This is a warning Second input line of warning </p> <p> <b>!Danger!</b> This is danger </p> ---------------------------------------------------------------------- == comments == 60 column format: ---------------------------------------------------------------------- Some text. Some indented text. Empty comment above ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- Some text. Some indented text. Empty comment above ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <p> Some text. </p> <p> Some indented text. </p> <p> Empty comment above </p> ---------------------------------------------------------------------- === === ======================================== a b c === === ======================================== 1 2 3 foo bar baz this list is very very very long man === === ======================================== == table == 60 column format: ---------------------------------------------------------------------- a b c ------------------------------------------------ 1 2 3 foo bar baz this list is very very very long man ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- a b c ------------------------------ 1 2 3 foo bar baz this list is very very very long man ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <table> <tr><td>a</td> <td>b</td> <td>c</td></tr> <tr><td>1</td> <td>2</td> <td>3</td></tr> <tr><td>foo</td> <td>bar</td> <td>baz this list is very very very long man</td></tr> </table> ---------------------------------------------------------------------- = ==== ====================================== s long line goes on here xy tried to fix here by indenting = ==== ====================================== == table+nl == 60 column format: ---------------------------------------------------------------------- s long line goes on here xy tried to fix here by indenting ---------------------------------------------------------------------- 30 column format: ---------------------------------------------------------------------- s long line goes on here xy tried to fix here by indenting ---------------------------------------------------------------------- html format: ---------------------------------------------------------------------- <table> <tr><td>s</td> <td>long</td> <td>line goes on here</td></tr> <tr><td></td> <td>xy</td> <td>tried to fix here by indenting</td></tr> </table> ----------------------------------------------------------------------