OpenMDAO V3 is a little inconsistent with it use of val and value as keyword arguments to different API methods. We are going to fix this in V4 by standardizing on val for everything. This change is proposed in POEM 050.
Unfortunately, that is going to cause some “minor” backwards incompatibility for any user code that specifically called out the value keyword. So in V3.11 and higher, we’ll keep backwards compatibility with the old keyword and give you a deprecation warning. This should provide a smooth upgrade path, since you can try out the new code and work to remove the deprecations.
We recognize that these kind of API changes are modestly annoying, but we feel they are a net positive in the long run because don’t have to guess which keyword to use where. If you don’t agree with us, or have an alternate proposal then feel free to chime in with comments or PRs on POEM 050.
