Issue #5206 has been updated by usa (Usaku NAKAMURA).

Status changed from Closed to Assigned

I think that it is good for warning, but isn't only the time of -w option being specified? 

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Feature #5206: ruby -K should warn
https://bugs.ruby-lang.org/issues/5206#change-27743

Author: drbrain (Eric Hodel)
Status: Assigned
Priority: Normal
Assignee: naruse (Yui NARUSE)
Category: core
Target version: 


When ruby is run with -K it changes the default encoding of all files even when that may be incompatible with the source.  If many libraries are used -K may cause incorrect behavior.

Now that we have the "coding:" magic comment ruby should warn if the -K flag is used and suggest that "coding:" magic comment be used instead.


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