Font problem prevents gnucash 1.8.12 from starting in Debian unstable

[Adam Rosi-Kessel]

After a recent Debian unstable upgrade, gnucash no longer starts.

The error log is below. Any ideas how to fix this quickly? I expect this
is more of a Debian issue than a gnucash-specific issue, but I don't
really know where to begin to find out which package is responsible.

My locale is set to 'C' -- I'm not sure where the LC_CTYPE=en_US is
coming from.

The font "-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Warning: gnucash_style_set_register...(): Cannot load font: -adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*

The font "-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Fatal Error: gnucash_style_set_register...(): Cannot load fallback font: -adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*

The font "-adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Warning: gnucash_style_set_register...(): Cannot load font: -adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*

The font "-adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Fatal Error: gnucash_style_set_register...(): Cannot load fallback font: -adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*

The font "-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Fatal Error: gnucash_style_set_register...(): Cannot load fallback font: -adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*

The font "-adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*" does not support all the required character sets for the current locale "LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=C;LC_IDENTIFICATION=C"
  (Missing character set "ISO8859-1")
  (Missing character set "ISO8859-1")
Fatal Error: gnucash_style_set_register...(): Cannot load fallback font: -adobe-helvetica-medium-o-normal--*-120-*-*-*-*-*-*