--sh-boot --venv=... --include-tools pex doesn't respect PEX_TOOLS=1 if venv exists

[huonw]

If a PEX is built with --sh-boot --venv=... --include-tools, then running PEX_TOOLS=1 ./path/to/pex only works if the venv hasn't already been created in $PEX_ROOT (that is, the cache is cold).

If the venv already exists, then the PEX_TOOLS=1 ./path/to/pex ... invocation is equivalent to ./path/to/pex ..., i.e. just invoking the pex normally without PEX_TOOLS=1.

I'd expect the state of the cache to not change the behaviour of these invocations (only the performance).

Reproducer:

#!/usr/bin/env bash

cd $(mktemp -d)

python3.12 -m venv venv
. venv/bin/activate
pip install pex==2.33.6

pex --include-tools --sh-boot --venv=prepend -o example.pex

export PEX_ROOT=./pex_root

echo "OKAY: PEX_ROOT empty: request for tools works"
PEX_TOOLS=1 ./example.pex -h
# usage: PEX_TOOLS=1 ./example.pex [-h] [-V] ...
# ...

# Seed the venv
./example.pex -c ''

echo "BUG: PEX_ROOT seeded: request for tools ignored (Python help instead)"
PEX_TOOLS=1 ./example.pex -h
# usage: .../python [option] ... [-c cmd | -m mod | file | -] [arg] ...
# ...

The bug stops reproducing after removing any of the options.

[jsirois]

Facepalm. Thanks for reporting and fixing @huonw!