Error if `related` field references key with Unicode characters

[anghyflawn]

In biber v. 2.7 (from Arch Linux repos), attempting to reference sériot2014east in the following set of entries:

@Book{sériot2014east,
  author       = {Sériot, Patrick},
  subtitle     = {East, west and non-{Darwinian} biology in the origins of structural linguistics},
  title        = {Structure and the whole},
  related      = {sériot2012structure},
  relatedtype  = {translationof},
  year         = 2014,
  translator   = {Jacobs-Colas, Amy},
  location     = {Berlin},
  publisher    = {Mouton}
}

@Book{sériot2012structure,
  author       = {Sériot, Patrick},
  title        = {Structure et totalité},
  edition      = {2},
  subtitle     = {Les origines intellectuelles du structuralisme en {Europe} centrale et orientale},
  year         = 2012,
  location     = {Limoges},
  publisher    = {Lambert-Lucas}}

produces an error

Wide character in subroutine entry at /usr/share/perl5/vendor_perl/Biber/Entry.pm line 97

If the é is removed from the related field:

@Book{sériot2014east,
  author       = {Sériot, Patrick},
  subtitle     = {East, west and non-{Darwinian} biology in the origins of structural linguistics},
  title        = {Structure and the whole},
  related      = {seriot2012structure},
  relatedtype  = {translationof},
  year         = 2014,
  translator   = {Jacobs-Colas, Amy},
  location     = {Berlin},
  publisher    = {Mouton}
}

@Book{seriot2012structure,
  author       = {Sériot, Patrick},
  title        = {Structure et totalité},
  edition      = {2},
  subtitle     = {Les origines intellectuelles du structuralisme en {Europe} centrale et orientale},
  year         = 2012,
  location     = {Limoges},
  publisher    = {Lambert-Lucas}}

then everything compiles fine. I suspect the error has to do with the fact that md5_hex doesn't like Unicode characters, but I don't know any Perl, sorry!

[plk]

Was a bug - can you try dev 2.8 version? You will need dev biblatex 3.8 too.

[anghyflawn]

Now this works. Thanks!