zipapp exploded the python interpreter

[gfrankliu]

We are using python 3.10 and the static python3 interpreter binary is about 45MB, but zipapp packs it three times so we end up with 150MB just for the interpreter alone, making the zipapp binary bloated.

$ ls -l runfiles/rules_python++python+python_3_10_x86_64-unknown-linux-gnu/bin/python*
-rwxrwxr-x 1 koi koi 44667000 Jan  1  1980 python
-rwxrwxr-x 1 koi koi 44667000 Jan  1  1980 python3
-rwxrwxr-x 1 koi koi     3149 Jan  1  1980 python3-config
-rwxrwxr-x 1 koi koi 44667000 Jan  1  1980 python3.10
-rwxrwxr-x 1 koi koi     3149 Jan  1  1980 python3.10-config

Also the static interpreter wouldn't need the shared libraries, but that is also being packed into zipapp, increase the size by another 45MB:

$ ls -l runfiles/rules_python++python+python_3_10_x86_64-unknown-linux-gnu/lib/
-rwxrwxr-x  1 koi koi 45131088 Jan  1  1980 libpython3.10.so.1.0
-rwxrwxr-x  1 koi koi    16800 Jan  1  1980 libpython3.so
-rwxrwxr-x  1 koi koi  2340016 Jan  1  1980 libtcl9.0.so
-rwxrwxr-x  1 koi koi  3082472 Jan  1  1980 libtcl9tk9.0.so
...

[aignas]

So there are 2 root causes:

• bin/python size exploded 2000 times larger #3534
• zip not handling symlinks correctly

Anything else to note here? I think the second bullet point is a new thing which should be scope of this ticket.