If you get error like:

Running sa-compile (may take a long time)
config: path “/var/lib/spamassassin/.spamassassin/user_prefs” is inaccessible: Permission denied
cannot create a directory: Permission denied at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1034.
cannot write to /var/lib/spamassassin/.spamassassin/sa-compile.cache/rules.body_0 at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1036.
print() on closed filehandle CACHE at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1037.
plugin: eval failed: error writing: Bad file descriptor at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1037.

/var/lib/spamassassin/compiled/5.014/
root@ns2:/home/hipo# apt-get upgrade clamav
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages have been kept back:
clamav clamav-base clamav-daemon clamav-freshclam
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? Y
Setting up spamassassin (3.3.2-5+deb7u3) …
Running sa-compile (may take a long time)
config: path “/var/lib/spamassassin/.spamassassin/user_prefs” is inaccessible: Permission denied
cannot create a directory: Permission denied at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1034.
cannot write to /var/lib/spamassassin/.spamassassin/sa-compile.cache/rules.body_0 at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1036.
print() on closed filehandle CACHE at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1037.
plugin: eval failed: error writing: Bad file descriptor at /usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm line 1037.

Solution is

chown -R root:root /var/lib/spamassassin/compiled/5.014/

Then re-run apt-get update && apt-get upgrade