Re: Question WHY is gnu make does not stop on error on rule

[aotto]

On 08.12.22 20:21, Paul Smith wrote:
> On Thu, 2022-12-08 at 19:59 +0100, aotto wrote:
> > HA HA HA - I fund the bug !!
> >
> > I used "-silent" and not "--silent", the "-silent" is parsed as
> That's funny, but I'm not sure why it works differently in 4.4 since
> that was still the case in 4.3, if you use "-silent".
>
> > MqC.mq.$(MAKE_LNG): | MqC.mq.$(MAKE_LNG).before MqC.mq.$(MAKE_LNG).after
> This usage is dangerous, because:
>
>    $ false
>    $ echo $?
>    1
>
>    $ false | cat
>    $ echo $?
>    0
>
> See how the pipeline swallowed the failing exit code?  The exit code of
> a pipeline is always the exit code of the last statement in the
> pipeline (here, the "cat" program).
>
> If you want to require bash you can use something like:
>
>    SHELL := /bin/bash
>    .SHELLFLAGS = -o pipefail -c
>
> which will force the exit code of a pipeline to be the exit code of the
> last failing command, not the last command.
>
> If you don't want to require bash, you'll have to get a LOT fancier
> than simply adding a pipe in a variable, if you want to preserve exit
> codes.
the "|" is not the bash-"|" it is the rule prerequisite "|"

www.gnu.org/software/make/manual/html_node/Prerequisite-Types.html


ao