[Mobile-sig] [Python-Dev] Import Fails in setup.py On Android

[Cyd Haselton]

Additionally, for reference purposes, here is a link to technical information on the environment that I am using:
http://kevinboone.net/kbox2_how_it_works.html


On February 7, 2015 5:36:50 AM CST, Cyd Haselton <chaselton at gmail.com> wrote:
>Hello Russ,
>Thanks for the update.
>
>I'm building Python 3.4.2 from sources, (using a GCC that I originally
>ported, then upgraded on device) on an Android device in an environment
>that simulates a Linux filesystem using fakechroot (Terminal Emulator
>and KBOX); Python is not currently installed in this environment.
>
>I've built other utilities in this environment successfully; the key is
>making sure that anything that requires dlopen() is built with shared
>libraries and is linked with -lc -ldl, as Android's dlopen() is not in
>its libc but in -ldl. The shared part is due to a limitation of the
>libfakechroot that the KBOX environment uses; anything calling dlopen()
>without the necessary links will cause fakechroot to terminate the
>process and throw an undefined symbol error
>
>For the Python build I've specified -lc -ldl in the appropriate
>environmental variables, in Modules/Setup and in setup.py.  The initial
>python binary is built, but it fails (with the undefined ref to
>dlopen()) when importing the extension modules it has has built.  I
>have run nm on those modules and...even though -lc -ldl is on the
>extension build command line...the dlopen() symbol is not there.
>
>Sorry for the long explanation. Let me know if there's info I've left
>out.
>
>
>
>On February 6, 2015 8:10:16 PM CST, Russell Keith-Magee
><russell at keith-magee.com> wrote:
>>Hi Cyd,
>>
>>This list is as good a place as any for what you're describing.
>>
>>However, it's a little difficult to provide advice without stack
>traces
>>and
>>details of how you've built your Python build to start with. For
>>example,
>>are you cross compiling? If so, the problem you've described could be
>>caused by referencing the wrong Python instance when running setup.py.
>>
>>Yours,
>>Russ Magee %-)
>>
>>On Fri, Feb 6, 2015 at 3:46 AM, Cyd Haselton <chaselton at gmail.com>
>>wrote:
>>
>>> Also, if I've got the wrong list, please let me know.  Links to the
>>> correct list/lists are optional; I just want to know if this is the
>>> right place to get help so that I can keep searching if it isn't.
>>>
>>> On Thu, Feb 5, 2015 at 5:40 AM, Cyd Haselton <chaselton at gmail.com>
>>wrote:
>>> > Since i'm working on an Android tablet, I am forwarding the
>>original
>>> message
>>> > I sent to python-dev instead of re-typing the entire thing.
>>> >
>>> > To summarize: I'm building in a fakechroot environment on Android
>>that
>>> > supports dynamic calls to libc only. Something in the
>>> importlib._bootstrap
>>> > process is not linking to...or has not been linked to...the
>>necessary
>>> > libraries (I've checked the module...it is being linked to -lc
>>-ldl) but
>>> I
>>> > can't figure out what...as there's not a lot in the python docs on
>>it.
>>> >
>>> > I'm currently reading through the importlib docs but any help
>would
>>be
>>> > greatly appreciated.
>>> >
>>> > ________________________________
>>> > From: Eric Snow <ericsnowcurrently at gmail.com>
>>> > Sent: February 3, 2015 12:10:54 AM CST
>>> > To: Cyd Haselton <chaselton at gmail.com>
>>> > Cc: Python-Dev <python-dev at python.org>
>>> > Subject: Re: [Python-Dev] Import Fails in setup.py On Android
>>> >
>>> > On Mon, Feb 2, 2015 at 12:36 PM, Cyd Haselton
><chaselton at gmail.com>
>>> wrote:
>>> >>
>>> >>  After fixing a segfault issue (many thanks Ryan) I'm back to the
>>same
>>> >> issue
>>> >>  I was having with Python 2.7.8; the newly built python throws an
>>> >> undefined
>>> >>  reference to dlopen when running setup.py...specifically when
>>importing
>>> >>  just-built extensions
>>> >>
>>> >>  I've managed to narrow the problem down to the following line:
>>> >>
>>> >>  importlib._bootstrap._SpecMethods(spec).load()
>>> >
>>> >
>>> > That call is where modules are created (and executed) via the
>>loader
>>> > designated for the module by the import machinery.  So a problem
>>here
>>> > may simply reflect a problem with the loader.  Which module is
>>being
>>> > imported when you run into trouble?  Is it a C-extension module?
>>> >
>>> > Also keep in mind that
>>> > basically everything in importlib._bootstrap is
>>> > frozen into your Python binary when you build Python (or should
>>be).
>>> > So if you are seeing any errors related to something missing or
>>broken
>>> > in importlib._bootstrap, it could be related to the build step
>>where
>>> > importlib gets frozen.
>>> >
>>> > Either way, more info (e.g. a traceback) would be great if you
>need
>>more
>>> > help.
>>> >
>>> > -eric
>>> >
>>> >
>>> > --
>>> > Sent from my Android device with K-9 Mail. Please excuse my
>>brevity.
>>> _______________________________________________
>>> Mobile-sig mailing list
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>
>-- 
>Sent from my Android device with K-9 Mail. Please excuse my brevity.

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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