I followed the instructions on the backports instruction page:
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If you are using *etch* and you want apt to verify the downloaded
backports you can import backports.org archive’s key into apt:
gpg --keyserver hkp://subkeys.pgp.net --recv-keys 16BA136C
gpg --export | apt-key add -
or
wget -O - http://backports.org/debian/archive.key | apt-key add -
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but after executing the second option (or the second line of the first
option) I get the following messages:
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gpg: no writable keyring found: eof
gpg: error reading `-': general error
gpg: import from `-' failed: general error
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This occurs whether I run this as a normal user, or with sudo. What
am I doing wrong?