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Re: Concern about new g-b-s logging change - loss of error detection


Igor Pechtchanski wrote:
On Sat, 29 Oct 2005, Max Bowsher wrote:

Please forgive me if this has already been discussed - I've been
time-limited to scanning subject lines only recently.

Bourne shells consider only the exit status of the last command in a
pipeline when determining $? - this means that the addition of lots of
"| tee somefile" will cause errors occurring during the commands being
logged to be ignored.

This seems to me to be a more severe problem than not keeping the logs
in the first place - as a failing "make" could result in the packaging
of a partially built package.

Max,


Thanks for bringing this up.  This hasn't been discussed, and I admit I
missed this aspect of the problem when reviewing the patch.  I did have a
fleeting thought of changing the "tee"s to redirections, but didn't
realize the importance of this.  I just verified that even with "set -e"
in effect, bash will not terminate if an interior pipe command fails.

I can think of two ways to tackle this: use redirection (with the loss of
immediate console output),

I don't like that idea. When building a large package, this would mean many minutes without any feedback at all.


or use $PIPESTATUS (which is a bashism, and is
fragile, unless we use ${PIPESTATUS[$((${#PIPESTATUS[@]}-1))]}).

I think using a bashism is OK. Even people who don't actually use bash interactively will have it installed - it's in 'Base', after all.


Why would ${PIPESTATUS[1]} not be OK?

Max.


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