I’ve got two

pex_binary

targets that own the same script but supply different BUILD properties similar to:

pex_binary(
    name="do-the-thing",
    entry_point="file.py:main",
)
pex_binary(
    name="do-the-thing-arm64",
    entry_point="file.py:main",
    platforms=["linux_aarch64-cp-310-cp310"],
    # BUILD props ...
)

When running the underlying script directly e.g.

pants run file.py

is there a way I can detect the host platform and run the appropriate target? Bear in mind I’m on an older Pants version

2.17.0

so some of the new shiny environments features may not be available.

custom macro/plugin would work I think. • detect arch (probably using some Pants lib) • forward to pex_binary

you can also make the build graph "dynamic": • using

if ...:

or otherwise compute the `name`s differently • read environment variables with

env("NAME", optional_default_value)

(

.pants.bootstrap

can be used to set env vars via a shell script: https://www.pantsbuild.org/prerelease/docs/using-pants/key-concepts/options#pantsbootstrap-file) That said, the

pex_binary

configuration doesn't influence(*)

pants run file.py

, that always uses a "run on the current host" default configuration.

pants run path/to:do-the-thing

is the only way in which a pex is invoked (* this behaviour changed in Pants 2.x's lifetime... I'm pretty sure it was before 2.17, but potentially not, so I may be telling fibs)