Invalid "redefinition" error when importing different symbols from the same module with `import from`

[arnetheduck]

Nim Version

022a9c0

Description

from system/ansi_c import c_memchr
from system/ansi_c import CFilePtr

/home/runner/work/Nim/Nim/lib/std/syncio.nim(21, 13) Error: redefinition of 'ansi_c'; previous declaration here: /home/runner/work/Nim/Nim/lib/std/syncio.nim(18, 13)

https://github.com/nim-lang/Nim/actions/runs/20615705942/job/59207969199#step:10:13

Worked around by:

022a9c0

Current Output

Expected Output

Known Workarounds

No response

Additional Information

No response

[Araq]

You are supposed to use

from system/ansi_c import c_memchr, CFilePtr

This is not a bug.

[arnetheduck]

This is not a bug.

it's a pretty annoying "feature" then - see 30fa30f:

when defined(a):
  from X import xxx
...
when defined(b):
  from X import yyy

there's no good way to write the above without compromises

[arnetheduck]

also ..

import posix
import posix

this is fine.

[ringabout]

import posix
import posix
this is fine.

After #25178 and #25411, with -d:nimPreviewDuplicateModuleError, it becomes a compile-time error

[arnetheduck]

becomes a compile-time error

but .. why? a warning was just fine - there's no particular reason why this should be a hard error.

however, in this bug report, we're not considering the same import done twice - we're considering distinct / different symbols from the same module - doesn't quite make sense that we can't do the imports separately.