Hi I am facing with a very slow `run` goal completion time R

Question

Hi I am facing with a very slow `run` goal completion time Right now we have a python project with ~50 dependencies and 35 40k LOC When I run ` pants level=debug pex verbosity=9 run path to folder binary` it takes a whopping 70 80 secs to complete And when I add a print statement to the entry file it takes the same time 70 80 seconds I tried using `execution mode=venv` and `pex venv use symlinks=true` options but they didn t help Here is the timing details ```pex Building pex 8413 4ms pex Laying out PEX zipfile local dists pex 0 1ms pex Searching dependency cache Users serhat cache pants named caches pex root unzipped pexes 53b03e2e28c1a38ab2a682f3a8d615cd2ba49035 deps 0 0ms pex Resolving distributions 8325 8ms pex Parsing lock third party requirements macos arm64 lock 335 4ms pex Resolving requirements from lock file third party requirements macos arm64 lock 7974 6ms pex Parsing requirements 7 3ms pex Resolving urls to fetch for 48 requirements from lock third party requirements macos arm64 lock 113 1ms pex Hashing pex 161 1ms pex Isolating pex 0 1ms pex Downloading 131 distributions to satisfy 48 requirements 43 7ms pex Categorizing 131 downloaded artifacts 1 0ms pex Building 27 artifacts and installing 393 7641 5ms pex Building distributions for pex Installing 131 distributions 7594 7ms pex Vendoring attr from VendorSpec key= attrs requirement= git+ rewrite=True constrain=False constraints=None Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored attrs pex Vendoring packaging from VendorSpec key= packaging requirement= packaging==20 9 rewrite=True constrain=True constraints= pyparsing lt 3 Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored packaging pex Vendoring pyparsing from VendorSpec key= packaging requirement= packaging==20 9 rewrite=True constrain=True constraints= pyparsing lt 3 Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored packaging pex Vendoring pkg resources from PreparedGit key= setuptools requirement= git+ rewrite=True constrain=False constraints=None Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored setuptools pex Vendoring setuptools from PreparedGit key= setuptools requirement= git+ rewrite=True constrain=False constraints=None Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored setuptools pex Vendoring wheel from VendorSpec key= wheel requirement= wheel==0 37 1 rewrite=False constrain=True constraints=None Users serhat cache pants named caches pex root installed wheels 6a3c9545f9bc666f039874243789bf4ba5cc4fbde5a945eca40a651de360568b pex 2 1 103 py2 py3 none any whl pex vendor vendored wheel Saving PEX file to pex Zipping PEX file pex Zipping PEX file 53163 6ms 16 22 24 36 DEBUG Completed pants backend python util rules pex build pex 16 22 24 36 DEBUG Dependency rule pants backend python util rules pex create pex of Some rule pants backend python goals package pex binary package pex binary changed 16 22 24 36 DEBUG Completed pants backend python goals package pex binary package pex binary 16 22 24 36 DEBUG Dependency rule pants backend python goals package pex binary package pex binary of Some rule pants backend python goals run pex binary create pex binary run request changed 16 22 24 37 DEBUG Completed pants backend python goals run pex binary create pex binary run request 16 22 24 76 DEBUG Completed setup sandbox 16 22 37 42 DEBUG Completed `run` goal 16 22 37 42 DEBUG computed 1 nodes in 78 639370 seconds there are 12360 total nodes ``` Is this normal It s my first time working and trying to adopt pants in our monorepo We use bazel right now

happy-kitchen-89482 · Answer

Hi Is this happening every time you ` pants run` Or just the first time for a given target

breezy-window-26318 · Answer

It happens every time

happy-kitchen-89482 · Answer

Even if you make no changes at all

happy-kitchen-89482 · Answer

E g if you run ` pants run path to folder binary` twice in a row with no changes

breezy-window-26318 · Answer

No if I make no changes it runs immediately

happy-kitchen-89482 · Answer

And which version of Pants is this

breezy-window-26318 · Answer

2 14 0rc1

happy-kitchen-89482 · Answer

OK so I think this is because `run` on a `pex binary` target now has the behavior of build the full pex and then run it so it exactly emulates doing those two things separately

happy-kitchen-89482 · Answer

But you can also ` pants run path to folder binary py`

happy-kitchen-89482 · Answer

And that I believe doesn t build a full pex but runs directly from your source tree

happy-kitchen-89482 · Answer

ccing < bitter ability 32190> to confirm

happy-kitchen-89482 · Answer

And in that case no pex rebuilding happens when only first party sources change

happy-kitchen-89482 · Answer

It looks like maybe your 3rdparty deps are large so pex rebuilding is taking some time

happy-kitchen-89482 · Answer

Are you using a lockfile That pushes the resolve to lockfile generation time and then pex rebuilding should be a lot faster

happy-kitchen-89482 · Answer

So two things to try 1 Using a lockfile if you re not already 2 Running the file not the target

happy-kitchen-89482 · Answer

See here for 2 <https www pantsbuild org docs python run goal execution semantics>

breezy-window-26318 · Answer

It worked immediately thank you

breezy-window-26318 · Answer

I am using lockfile too

bitter-ability-32190 · Answer

I can pretty much guarantee the majority of the time is spent zipping the PEX That s what I ve seen Benjy is right though I d just run the py file

breezy-window-26318 · Answer

Yes thank you I never thought about just running the py file It s old bazel habits slightly smiling face

bitter-ability-32190 · Answer

If you need to run the binary I suggest using a different layout

bitter-ability-32190 · Answer

No worries it s a fairly new change slightly smiling face

bitter-ability-32190 · Answer

Also to confirm my suspicion gt ```pex Zipping PEX file 53163 6ms``` gt

breezy-window-26318 · Answer

slightly smiling face

happy-kitchen-89482 · Answer

< breezy window 26318> If you ` pants package` that target how big is the resulting pex file

breezy-window-26318 · Answer

Around 500mbs

happy-kitchen-89482 · Answer

OK so it taking some time just to zip up makes sense

enough-analyst-54434 · Answer

It says on the tin ~50s to zip in the OP output Have you tried `layout= packed `

bitter-ability-32190 · Answer

Oh by the way < breezy window 26318> one cool thing about being able to run Python files now is you likely need very few `pex binary` targets Only for things you really want to package

busy-vase-39202 · Answer

Since other people accustomed to Bazel may share these expectations may I suggest adding more clarification to the docs about the significant perf difference between running the file vs the target

breezy-window-26318 · Answer

Ah thank you This is great to know I will try packed option too