[cctbxbb] some thoughts on cctbx and pip

Graeme.Winter@Diamond.ac.uk Graeme.Winter at diamond.ac.uk
Thu Aug 22 22:17:04 PDT 2019


Without discussing the merits of this or whether we _choose_ to make the move to supporting PIP, I am certain it would be _possible_ - many other packages make dispatcher scripts when you pip install them e.g.

Silver-Surfer rescale_f2 :) $ which black; cat $(which black)
/Library/Frameworks/Python.framework/Versions/3.6/bin/black
#!/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6

# -*- coding: utf-8 -*-
import re
import sys

from black import main

if __name__ == '__main__':
    sys.argv[0] = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv[0])
    sys.exit(main())

So we _could_ work around the absence of LIBTBX_BUILD etc. in the system. Whether or not we elect to do the work is a different question, and it seems clear that here are very mixed opinions on this.

Best wishes Graeme


On 23 Aug 2019, at 01:21, Luc Bourhis <luc_j_bourhis at mac.com<mailto:luc_j_bourhis at mac.com>> wrote:

Hi,

Even if we managed to ship our the boost dynamic libraries with pip, it would still not be pip-like, as we would still need our python wrappers to set LIBTBX_BUILD and LD_LIBRARY_PATH. Normal pip packages work with the standard python exe. LD_LIBRARY_PATH, we could get around that by changing the way we compile, using -Wl,-R, which is the runtime equivalent of build time -L. That’s a significant change that would need to be tested. But there is no way around setting LIBTBX_BUILD right now. Leaving that to the user is horrible. Perhaps there is a way to hack libtbx/env_config.py so that we can hardwire LIBTBX_BUILD in there when pip installs?

Best wishes,

Luc


On 16 Aug 2019, at 22:47, Luc Bourhis <luc_j_bourhis at mac.com<mailto:luc_j_bourhis at mac.com>> wrote:

Hi,

I did look into that many years ago, and even toyed with building a pip installer. What stopped me is the exact conclusion you reached too: the user would not have the pip experience he expects. You are right that it is a lot of effort but is it worth it? Considering that remark, I don’t think so. Now, Conda was created specifically to go beyond pip pure-python-only support. Since cctbx has garnered support for Conda, the best avenue imho is to go the extra length to have a package on Anaconda.org<http://anaconda.org/>, and then to advertise it hard to every potential user out there.

Best wishes,

Luc


On 16 Aug 2019, at 21:45, Aaron Brewster <asbrewster at lbl.gov<mailto:asbrewster at lbl.gov>> wrote:

Hi, to avoid clouding Dorothee's documentation email thread, which I think is a highly useful enterprise, here's some thoughts about putting cctbx into pip.  Pip doesn't install non-python dependencies well.  I don't think boost is available as a package on pip (at least the package version we use).  wxPython4 isn't portable through pip (https://wiki.wxpython.org/How%20to%20install%20wxPython#Installing_wxPython-Phoenix_using_pip).  MPI libraries are system dependent.  If cctbx were a pure python package, pip would be fine, but cctbx is not.

All that said, we could build a manylinux1 version of cctbx and upload it to PyPi (I'm just learning about this).  For a pip package to be portable (which is a requirement for cctbx), it needs to conform to PEP513, the manylinux1 standard (https://www.python.org/dev/peps/pep-0513/).  For example, numpy is built according to this standard (see https://pypi.org/project/numpy/#files, where you'll see the manylinux1 wheel).  Note, the manylinux1 standard is built with Centos 5.11 which we no longer support.

There is also a manylinux2010 standard, which is based on Centos 6 (https://www.python.org/dev/peps/pep-0571/).  This is likely a more attainable target (note though by default C++11 is not supported on Centos 6).

If we built a manylinuxX version of cctbx and uploaded it to PyPi, the user would need all the non-python dependencies.  There's no way to specify these in pip.  For example, cctbx requires boost 1.63 or better.  The user will need to have it in a place their python can find it, or we could package it ourselves and supply it, similar to how the pip h5py package now comes with an hd5f library, or how the pip numpy package includes an openblas library.  We'd have to do the same for any packages we depend on that aren't on pip using the manylinux standards, such as wxPython4.

Further, we need to think about how dials and other cctbx-based packages interact.  If pip install cctbx is set up, how does pip install dials work, such that any dials shared libraries can find the cctbx libraries?  Can shared libraries from one pip package link against libraries in another pip package?  Would each package need to supply its own boost?  Possibly this is well understood in the pip field, but not by me :)

Finally, there's the option of providing a source pip package.  This would require the full compiler toolchain for any given platform (macOS, linux, windows).  These are likely available for developers, but not for general users.

Anyway, these are some of the obstacles.  Not saying it isn't possible, it's just a lot of effort.

Thanks,
-Aaron

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb


-- 
This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. 
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom



More information about the cctbxbb mailing list