[cmake-developers] Review Request: Topic ExternalProject-independent-step-targets

[David Cole]

> Please review the topic ExternalProject-independent-step-targets.


Looks mostly reasonable. However, I'm concerned people will misuse it 
to try to make all step targets "independent" when they shouldn't... 
configure of project B usually depends on a successful install of 
project A when B depends on A, and the target dependencies are the only 
thing making sure things work properly for parallel builds. The file 
dependencies alone are not sufficient. People *WILL* run into parallel 
build issues if they accidentally make something independent when it 
shouldn't be. (And it will probably be difficult to 
troubleshoot/debug...)

So I would add to the documentation saying that typically, only the 
download and update steps ought to be considered as "independent" step 
targets.

Also, I would ask Brad if the "-# ::" line you've removed is important 
for the new documentation generation scheme... I would assume so, but I 
do not know enough about how it works yet.


HTH,
David C.