[New-bugs-announce] [issue19027] undefined symbol: _PyParser_Grammar

[Armin Rigo]

New submission from Armin Rigo:

It is possible to get the working copy of Python 2.7 in a state such that any attempt to do "make" ends with the error shown in the title.  The working copy is perfectly valid; it is a matter of getting the wrong timestamps on the files.

(Despite the error message, this is not directly related to issue10013 or "make -j".)

I didn't try Python 3.x, but the same issue might apply.

How to reproduce:

- get your checkout, let's say in python/src/

- go to your build directory, say python/build/, and run "../src/configure; make".

- then, in the src dir, give Include/graminit.h a more recent timestamp than Python/graminit.c, for example by saying "touch Include/graminit.h" (this is the crux: a common mercurial checkout will order them the other way, just because of alphabetical ordering).

- remove your python/build/ directory completely, create it anew, and run again "../src/configure; make".

The cause of the message is that the Makefile rule for $(GRAMMAR_C) runs, because the GRAMMAR_H file is more recent; but the GRAMMAR_H rule does nothing, because the latter is already up-to-date.  So the only thing that runs is "touch $(GRAMMAR_C)".  But this creates an empty file build/Python/graminit.c!

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components: Interpreter Core
messages: 197797
nosy: arigo
priority: normal
severity: normal
status: open
title: undefined symbol: _PyParser_Grammar
type: compile error
versions: Python 2.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue19027>
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