SASL support: postconf -a or -A returns nothing

[John Gateley]

I'm just starting to work on SASL support, and tried the postconf -A and 
-a commands
to make sure SASL support was enabled at build time. It wasn't, both 
commands return
nothing (and no error code).

I can't find any steps for telling postfix to build with SASL support 
enabled in the docs.

Is this enabled manually? Or is it not finding the right library?

Dovecot is installed (debian package dovecot-imapd).

Thanks

John