#2044 Implement support for incremental lock resolves. Issue created by jsirois The basic idea here is to add a new

--lock <PATH>

flag to

pex3 lock create

and use the lock specified for

pex3 lock update <PATH>

to implement faster resolves by: 1. Create a venv from the existing lock that includes the configured Pip version. 2. Instead of performing an isolated

pip download --log ...

, perform a

pip install --log

in the venv created in step 1. 3. Merge the changes recorded in the pip log to the original lock file. It turns out this is a good deal faster than performing isolated

pip downloads

. The example from #2036 shows ~3x speedup with a warm re-lock today taking 22s vs a warm venv + pip install taking ~7s. This factor will likely drop closer to 2.5 once the additional overheads of processing lock diffs are added in, but it seems likely this will still net a significant win. pantsbuild/pex