I'm troubleshooting a slow pex build:

Building 34 requirements for requirements.pex from the 3rdparty/python/default.lock resolve: ..

takes much longer than it should in CI. I'm trying to figure out if there is a dependency that is compiling from scratch, and need more verbose output. I tried

PEX_VERBOSE=100 pants --level=debug --no-pantsd ...

but that didn't quite do it. How can I get more info about what is happening during that build stage?

There's always the

--keep-sandboxes=always

option which will keep the execution environment for you to poke around in. Although if it only happens in an ephemeral CI runner it might not help. Also does the https://www.pantsbuild.org/2.20/reference/subsystems/pex#verbosity Arg help? I'm on mobile and can't test

A not particularity fancy approach would be grep-ing the lockfile for source distrocs aka Not Wheels. That would narrow down the possibilities, although not tell you which is "slow".