[Scons-users] cache + sideeffect not working as expected ?

[Julien Pommier]

Dirk wrote :

> Some additional info about SideEffect: it is a method reserved for the 

> special case where your build step emits not only the required target, 

> but also an additional file(s) which always carries the same name 

> (e.g. "default.h"), no matter how the names of your sources and 

> targets look like.

> When you wanted to use the "-j" option, this could lead to trouble if 

> several threads tried to create and write to the same file at once. By 

> marking the "default.h" as SideEffect(), SCons ensures that only one 

> thread creating/writing "default.h" can run at the same time.


Thanks a lot for your explanation, Dirk, It looks like I did not 
understand the purpose of the SideEffect command. It is now very clear , 
and


> env.Command(['foo','bar'], [], 'touch foo && touch bar')


is exactly what I was trying to achieve !

Julien