Building Python 3 on old distributions

[Siddhesh Poyarekar]

On Friday 07 September 2018 11:50 PM, Joseph Myers wrote:
> One question asked at today's glibc BoF at the Cauldron was how hard it
> was to build Python 3 on old GNU/Linux distributions, should we require it
> for the glibc build.
> 
> I tried building Python 3.7.0 on Ubuntu 10.04, as the oldest distribution
> I have readily to hand for testing such things.  I needed to build libffi
> 3.2.1 first:
> 
> ./configure --prefix=/scratch/jmyers/python-install
> make
> make install
> 
> and then could build Python 3.7.0:
> 
> ./configure --prefix=/scratch/jmyers/python-install CPPFLAGS=-I/scratch/jmyers/python-install/lib/libffi-3.2.1/include LDFLAGS="-L/scratch/jmyers/python-install/lib -Wl,-rpath,/scratch/jmyers/python-install/lib"
> make -j8
> make install
> 
> The resulting Python does not support the ssl module (OpenSSL is too old
> and I didn't try building newer OpenSSL locally).  It *does* support
> hashlib.

We should not need openssl support to build glibc, so this shouldn't be 
a problem.

It might be a good idea to make a list of modules that are allowed when 
writing scripts directly related to build or bootstrap, maybe starting 
with the following:

- os
- sys
- argparse
- subprocess
- time
- io
- re

and then adding as required, keeping the list as small as possible.

Siddhesh