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(pardon any awkward formatting, writing from webinterface instead of a |
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"proper" client. Please yell at me off-list or on irc if this post is |
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excessively broken.) |
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|
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> https://bugs.gentoo.org/show_bug.cgi?id=300922 |
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|
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From that bug: |
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|
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> - chpathtool does some "simple" heuristic to switch the build EPREFIX |
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> to the new target EPREFIX |
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> |
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> - python (seemingly) doesn't like when the pyc files are changed and *not* regenerated. |
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> You will see the message: "Bad marshalling data" |
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|
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I'm not sure if I'm interpreting this correctly, but it sounds as if |
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your chpathtool edits the .pyc file to replace the path? If yes: that |
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will indeed not work, as strings are stored length-prefixed. You |
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cannot sensibly edit .pyc files, you should normally just rewrite |
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them. |
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|
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The .pyc/.pyo file store a version-dependent magic, the mtime of their |
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corresponding .py file, and (since recently) the size of the |
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correspondig .py file. If either changes the .pyc/.pyo is regenerated. |
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The magic does not normally change in released pythons, so that's not |
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much of a problem. The mtime is probably no longer a problem these |
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days either. |
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|
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There used to be a more subtle problem: the python objects you import |
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have the path to their source embedded into them, and if you move the |
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.pyc/.pyo file around that path would be wrong, confusing some (mostly |
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debugging) tools (see http://bugs.python.org/issue1180193 ). This was |
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fixed fairly recently (in python 3, python 2.7 and python 2.6.2), so |
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it is probably no longer worth worrying about, but it's probably one |
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reason these files were handled this way in the past. |
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|
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-- |
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Marien Zwart (marienz) |
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