[Scons-users] Fwd:Re: timing issues and protecting from them

[Tom Tanner (BLOOMBERG/ LONDON)]

Thanks. I'll start poking around in those places.

And yes, an indirect dependency can safely change because it isn't part of your signature. Only the direct dependencies are.

Consider:

a,o depends on a.hh, a.cc
a.lib depends on a.o

scons starts build
scons builds a.o and updates tree
idiot^H^H^H^H^Huser changes a.hh
scons build a.lib

You don't have an inconsistency. You do have a requirement to rebuild, but nothing is inconsistent.


From: dl9obn at darc.de At: Dec 10 2015 10:39:05
To: scons-users at scons.org
Subject: Re: [Scons-users] Fwd:Re: timing issues and protecting from them

Tom,

On 10.12.2015 09:13, Tom Tanner (BLOOMBERG/ LONDON) wrote:
> Well, I can check the timing for that. But I don't see a necessity for 
rechecking the indirect dependencies
>

so an indirect dependency may change during a build, but a direct source not? 
This doesn't really make sense to me...but I 
understand where you're coming from. You have experienced this phenomenon of 
"hard to track down" build errors several times now, 
and want to do something about it. So please, as I mentioned in my earlier 
mail, start on an implementation for this feature if you 
find the time. The execute() and executed_with_callbacks() methods in the 
Taskmaster look like the best place to do that.
To me, this seems more like a job for the Taskmaster than putting new code in 
the Node() methods build()/built().
I'd derive a new ParanoidTaskmaster from the original class and then add my 
checks to that. This also includes generalizing the 
creation of the "Taskmaster" in the Main.py script, such that you can select 
between the "default" and your new version via a 
command-line switch.

Finally, the really paranoid people clearly separate builds from their edit 
cycles by building the final stuff on a different server 
for example. I happen to work in one of those places ;)...and we always build 
against fixed labels.

Best regards,

Dirk

_______________________________________________
Scons-users mailing list
Scons-users at scons.org
https://pairlist4.pair.net/mailman/listinfo/scons-users


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://pairlist4.pair.net/pipermail/scons-users/attachments/20151210/0d28f9f8/attachment-0001.html>