In #19309 a separate output for tkinter was added.
Several dependencies of Python depend indirectly on Python. We have the
following two paths:
```
‘python-2.7.12’ - ‘tk-8.6.6’ - ‘libXft-2.3.2’ - ‘libXrender-0.9.10’ -
‘libX11-1.6.4’ - ‘libxcb-1.12’ - ‘libxslt-1.1.29’- ‘libxml2-2.9.4’ -
‘python-2.7.12’
‘python-2.7.12’ - ‘tk-8.6.6’ - ‘libXft-2.3.2’ - ‘fontconfig-2.12.1’ -
‘dejavu-fonts-2.37’ - ‘fontforge-20160404’ - ‘python-2.7.12’
```
Because only `tkinter` needs this, I added
```
pythonSmall = python.override {x11Support = false;};
```
to break the infinite recursion. We also still have the output
`tkinter`.
However, we might as well build without x11Support by default. Then we build with x11Support as well so we get the tkinter module and put that in a separate package.
Compiling python with "-Wl,-stack_size,1000000" causes problems when
compiling for example pygobject3. pygobject3 uses "python3.x-config
--ldflags" during installation and then fails when
"-Wl,-stack_size,1000000" is present. Maybe we should investigate
removing this during the build of pyobject3, but this stack_size flag is
also not used on the popular darwin homebrew-core channel for python3.5,
so it seems safe to remove it.
The previous commit revealed that Python wasn't actually using
Berkeley DB; it only had it in its closure due to the build-time flag
dump in Makefile and _sysconfigdata.py. When Python detects both GNU
gdbm and Berkeley DB at build time, it will use the former.
This reduces Python's closure size from 200 MiB to 129 MiB. Even
better would be to get move tkinter to a separate output or package
(since that would get rid of all X11 stuff), but that's a bit harder.
Aneesh Agrawal
Frederik Rietdijk
Josef Kemetmueller
Eelco Dolstra