Debugging why KRB5_KTNAME isn't working

Brian J. Murrell brian at
Thu Jan 27 13:27:07 EST 2022

On Thu, 2022-01-27 at 13:03 -0500, Ken Hornstein wrote:
> Is it possible Postfix is clearing out the environment at startup?

As anything, I suppose it is possible.  It would be doing so in
violation of exactly the purpose of the mechanism that is being used to
set the environment though.  Meaning, the environment is not just being
set by the caller and Postfix is clearing it as a matter of good
housekeeping.  The variable is actually being specified in a for-
purpose Postfix configuration mechanism.  This mechanism is
specifically defined to set environment variables in Postfix processes.

I will ask the Postfix mailing list in any case.

> a very brief
> test suggests to me that "environ" contains the environment at
> process
> start and modification of the current environment isn't reflected
> there,

That's the result of my testing too.  I must admit to being a little
surprised at that though.  Seems to significantly diminish the
purpose/usefulness of that particular /proc entry.

> so if Postfix was resetting the environment you wouldn't know it


I wonder if you can suggest a simple test that would verify/demonstrate
the functionality of the KRB5_KTNAME env. var. that I can use in my
problem report to the Postfix devs.


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