Thank you for the reply!

Using it the way you describe will cause porting issues for older perl versions

You are correct that the :bsd_glob export tag wasn't added until Perl v5.16, sometime from File::Glob 1.13 to 1.17 in File::Glob 1.15. (Note you've got a typo in your example, -MFile::Glob::bsd_glob. fixed) But from the File::Glob docs:

The :glob tag, now discouraged, is the old version of :bsd_glob. It exports the same constants and functions, but its glob() override does not support iteration; it returns the last file name in scalar context.

So one backwards-compatible way to go is use File::Glob ':glob';, unless you want to use it in scalar context, which might not be a good idea anyway due to the issue choroba described.

$ touch 'foo bar.txt'
$ perl -MFile::Glob=:glob -e 'print for <*foo bar*>'
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This works in Perl 5.6.2 thru 5.24, and warns about the deprecation of :glob in 5.26. What you can do in Perl v5.6 thru v5.26 (and hopefully beyond) is either

use File::Glob 'bsd_glob';
print for bsd_glob('*foo bar*');
# -- or --
use File::Glob $] lt '5.016' ? ':glob' : ':bsd_glob';
print for <*foo bar*>;
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With the limitation of not being able to use the latter in scalar context until Perl v5.16 and up (Update: and the former not at all, unfortunately).

Does this in your opinion imply that File::Glob should be dual-lived?

No, I don't yet have a well-formed opinion either way.