Hey I am new to the pants ecosystem and I am trying to build

Question

Hey I am new to the pants ecosystem and I am trying to build a monorepo for my django projects Here is the dir structure that I have ``` 3rdparty python default lock BUILD pants pants toml poetry lock projects proj1 BUILD manage py proj1 BUILD init py asgi py settings py urls py wsgi py proj2 pyproject toml``` Here s my pants toml ``` GLOBAL pants version = 2 12 0 backend packages add = pants backend python anonymous telemetry enabled = false source root patterns = python enable resolves = true lockfile generator = pex python infer string imports = true``` Here s my projects proj1 BUILD ```pex binary name= manage entry point= manage py python sources ``` Here s my projects proj1 proj1 BUILD ```python sources ``` I am trying to run the runserver command with pants ``` pants run projects proj1 manage runserver``` But I am getting an error with stack trace ```Traceback most recent call last File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django core management base py line 354 in run from argv self execute args cmd options File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django core management commands runserver py line 61 in execute super execute args options File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django core management base py line 398 in execute output = self handle args options File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django core management commands runserver py line 68 in handle if not settings DEBUG and not settings ALLOWED HOSTS File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django conf init py line 82 in getattr self setup name File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django conf init py line 69 in setup self wrapped = Settings settings module File Users reksus cache pants named caches pex root installed wheels 115baf5049d5cf4163e43492cdc7139c306ed6d451e7d3571fe9612903903713 Django 3 2 15 py3 none any whl django conf init py line 170 in init mod = importlib import module self SETTINGS MODULE File Library Developer CommandLineTools Library Frameworks Python3 framework Versions 3 8 lib python3 8 importlib init py line 127 in import module return bootstrap gcd import name level package level File lt frozen importlib bootstrap gt line 1014 in gcd import File lt frozen importlib bootstrap gt line 991 in find and load File lt frozen importlib bootstrap gt line 961 in find and load unlocked File lt frozen importlib bootstrap gt line 219 in call with frames removed File lt frozen importlib bootstrap gt line 1014 in gcd import File lt frozen importlib bootstrap gt line 991 in find and load File lt frozen importlib bootstrap gt line 973 in find and load unlocked ModuleNotFoundError No module named proj1 ``` I tried updating the projects proj1 BUILD ```pex binary name= manage entry point= manage py dependencies= projects proj1 proj1 proj1 python sources ``` But still the same error What am I missing here

refined-addition-53644 · Answer

What are the import statements you are using I feel like it s imported as `from proj1 ` If that s the case then your `root patterns` should have `projects`

handsome-sunset-98068 · Answer

Yeah you are right since manage py has this line ```os environ setdefault DJANGO SETTINGS MODULE proj1 settings ``` which require projects proj1 to be in pythonpath so I fixed by updating pants toml ``` source root patterns = marker filenames = manage py ```

handsome-sunset-98068 · Answer

But now the command ``` pants run projects proj1 manage runserver``` thrown this error ```Traceback most recent call last File path to projects proj1 manage py line 11 in main from django core management import execute from command line ModuleNotFoundError No module named django ``` but this command is working ``` pants run projects proj1 manage runserver noreload``` Why is this

refined-addition-53644 · Answer

How do you define your 3rd party dependencies basically packages like Django Do you use `requirements txt` I don t see anywhere the code you have pasted here As mentioned in this doc you can see all the dependencies 1st and 2nd using `dependencies` command and it can be transitive too So I would debug using that <https www pantsbuild org docs python third party dependencies|https www pantsbuild org docs python third party dependencies>

handsome-sunset-98068 · Answer

I am using poetry top level pyproject toml ``` tool poetry name = monorepo version = 0 1 0 description = authors = Tarun Tyagi readme = README md tool poetry dependencies python = ^3 9 Django = ^3 2 build system requires = poetry core build backend = poetry core masonry api ``` top level BUILD ```pex binary name= django admin dependencies= poetry Django script= django admin poetry requirements name= poetry ```

refined-addition-53644 · Answer

Yeah so I would run `dependencies` command and see if `django` shows up or not Are you able to run it outside pants with just python

refined-addition-53644 · Answer

Ideally you wouldn t need to provide explicit dependency as long as pants can infer it

handsome-sunset-98068 · Answer

``` gt pants dependencies projects proj1 manage py poetry Django projects proj1 manage py projects proj1 proj1 init py projects proj1 proj1 asgi py projects proj1 proj1 settings py projects proj1 proj1 urls py projects proj1 proj1 wsgi py``` Maybe I didn t write my earlier message clearly This command doesn t work and says no module named django ``` pants run projects proj1 manage runserver``` But the following is working So I have this working now ``` pants run projects proj1 manage runserver noreload``` I am actually asking what difference does noreload make as far as pants is concerned And in the github example django the noreload flag is not required with runserver cmd so how can that be made possible here

refined-addition-53644 · Answer

Ah ok Sorry I might have also missed your question Yeah this I am not sure about Seems something django specific

handsome-sunset-98068 · Answer

No problem Shantanu thanks though Btw noreload simple stops reloading server on live code changes i e doens t update the code already loaded in memory Many languages have this live reloading feature Maybe this could help you in helping me find the fix

happy-kitchen-89482 · Answer

Ah yes if I remember correctly the way the Django autoreloader works interacts badly with Pants s hermetic sandboxes and gives that error the autoreloader has some very unusual syspath hacking

happy-kitchen-89482 · Answer

The way around this is to set `restartable=True` on the `pex binary` target <https www pantsbuild org docs reference pex binary coderestartablecode>

happy-kitchen-89482 · Answer

Then you get Pants itself to autoreload for you instead of the Django autoreloader

happy-kitchen-89482 · Answer

Pants is already watching the filesystem for changes and it knows about dependencies even Django doesn t know about so it can actually be more accurate than the Django autoreloader anyway

happy-kitchen-89482 · Answer

For example Pants will reload and rebuild as necessary when you change your pyproject toml and I don t think Django will

happy-kitchen-89482 · Answer

With Pants you get autoreloading even if the underlying framework doesn t have it