Sandbox has source not found for dateutil

[ndmitchell]

Describe the Bug

If you put this code in the sandbox:

from dateutil.relativedelta import relativedelta
print(relativedelta(days=1))

Then you get the error:

ERROR sandbox.py:1:1-49: Stubs for `dateutil.relativedelta` are bundled with Pyrefly but the source files for the package are not found. [[missing-source-for-stubs](https://pyrefly.org/en/docs/error-kinds/#missing-source-for-stubs)]

Does this make sense in the sandbox? If you then run it you get a failure:

The module 'python-dateutil' is included in the Pyodide distribution, but it is not installed.

Should we install it into Pyodide?

Sandbox Link

https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEmqALjAK5PSGUxTMQBuMTDyao6EGsVyUmdbrw6DhUUQB1064pQjomACnl8lI1Hsak4AXgCMASlsgANCHbQ4JcohABiOgFUOKAgmUjowVnQAYw5cdDh1dWEwMOkaZgB9dFYabBhKPXxEcV1bOgBaAD46OCZKRHU6RrkYJlZKdDDVEAA5bNy6umB8AF8u9ScQMm4wKFJCJlooCl8ABVJp2eqMHAI6SNjIAHM2vljCdV8AZRgYOgALJiZiOEQAelepmBm56UPXmHQr0wuEicFe%2B3QRxOMUBKUodFQ-FQ0FQ2FgewOEGOlFOHVwxBh7k0pCYd1iZUElDgEFidEsdC6AGZCNYAExjdAgYbOVDRAQwABi0BgFDQWDwRDIXKAA

(Only applicable for extension issues) IDE Information

No response

[AryanBagade]

hello @ndmitchell , can i work on it, been contributing to sandbox will have a look at it!

[ndmitchell]

Certainly, have assigned you @AryanBagade

[AryanBagade]

Hi @ndmitchell!

The fix:

Two approaches - which one do you prefer?

Option 1 (Simple - 1 line):

await py.loadPackage('python-dateutil');

Option 2 (Using micropip):

await py.loadPackage('micropip');
  await py.runPythonAsync(`
      import micropip
      await micropip.install('python-dateutil')
  `);

Also I'm unable to test locally due to SRI integrity check failures on Pyodide packages in the dev environment, but i believe the package fetching logic should be correct.

Which approach would you prefer? Or is there a different solution you'd recommend?

[yangdanny97]

Instead, the general advice is to use micropip.install() for everything except in the following cases where pyodide.loadPackage() might be more appropriate: to load micropip itself, when you are optimizing for size, do not want to install the micropip package, and do not need to install packages from PyPI with dependency resolution.

https://pyodide.org/en/stable/usage/loading-packages.html

Seems like the latter is preferable.

I'm more curious about how you plan to detect what packages the user needs, since we can't/shouldn't pre-install all the typeshed packages on sandbox load, that would take way too long

[AryanBagade]

@ndmitchell @yangdanny97 I'm unable to fully verify the fix locally due to SRI, i believe it will be tested and will work in ci production, also you can make changes to the code as well i made a pr with try catch debug setup