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Hello, developers. |
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The distutils-r1 eclass (and the python-r1 eclass used it to implement |
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it) have seen a few minor changes recently. Hopefully, they will make |
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Python ebuild writing easier and more predictable. |
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Firstly, we have completely removed the parallel run support. This |
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means that in particular: |
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a. all of python_* phases are always run in series. |
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b. python_parallel_foreach_impl() is deprecated, and works as alias to |
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python_foreach_impl(). You can replace it with the latter at any time. |
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c. DISTUTILS_JOBS and DISTUTILS_NO_PARALLEL_BUILD no longer have any |
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meaning. The former may be removed from make.conf, the latter from |
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ebuilds, |
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d. All non-local variables set within sub-phase functions will be |
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passed through to the next sub-phase executions. Please ensure to use |
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'local' whenever necessary ;). |
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The rationale can be found at [1]. Long story short, the parallel runs |
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gave real gains only in corner cases, while some more corner cases |
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required them disabled. They triggered a lot of bugs in build systems |
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which imposed a serious amount of work on our developers, and often |
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confused our users. |
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Secondly, we have added a clear guarantee that the working directory |
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is restored after each sub-phase function invocation returns. In other |
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words, you are free to 'cd' anywhere you want in a sub-phase function, |
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and you can safely assume that the next Python implementation will |
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start with the same initial directory, and that that directory will be |
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restored once distutils-r1_src_* leaves. |
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This is pretty much a bugfix for the first change. Since parallel runs |
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caused sub-phase functions to be run in subshells, the directory |
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changes within didn't affect the further calls. Additionally, |
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DISTUTILS_IN_SOURCE_BUILD restored working directory on leave. Since we |
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no longer have subshells and bugs started appearing, we decided to |
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remove these implicit conditionals and just preserve working directory |
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unconditionally. |
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Hope these changes make the eclasses a bit easier on you. We still have |
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over 250 distutils ebuilds to update [2]! Have fun. |
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[1]:http://thread.gmane.org/gmane.linux.gentoo.python/641 |
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[2]:http://dev.gentoo.org/~mgorny/python-r1/conversion.xhtml |
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-- |
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Best regards, |
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Michał Górny |
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