QUERY · ISSUE

BUG: sys.modules['sys'] not pointing import('sys')

openby pmp-popened 2019-07-16updated 2019-07-16

Probably the same reason as :
https://github.com/micropython/micropython/issues/4427

CANDIDATE · ISSUE

builtin modules don't show up in sys.modules when imported

closedby dhylandsopened 2015-12-31updated 2024-08-28

I noticed that when you import builtin modules, like sys, time, os, that they don't show up in sys.modules. Is this intentional?

In CPython, builtin modules show up like:

'_io': <module 'io' (built-in)>

Assessment

S Sonnet · medium

Both issues describe the same root cause: builtin modules are not properly registered in sys.modules during import. Issue #1759 reports the general case (sys, time, os don't appear in sys.modules at all), while #4923 reports a specific manifestation (sys.modules['sys'] exists but refers to a different object than import('sys') returns). The symptom differs slightly — absent vs. identity mismatch — but both stem from MicroPython's builtin module import path bypassing the sys.modules registration that CPython performs. They are likely resolved by the same fix. #1759 is the older, broader report.

Suggested action

Close #4923 as a duplicate of the older and more general #1759, unless #4923 demonstrates a distinct code path (identity mismatch rather than absence) that survives any fix applied to #1759. If a fix for #1759 has already been merged, verify it also resolves the identity-mismatch case before closing.

BUG: sys.modules['sys'] not pointing __import__('sys')

builtin modules don't show up in sys.modules when imported

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BUG: sys.modules['sys'] not pointing import('sys')