Is there documentation for [buildenv] in profiles?

[datalogics-kam]

I'm doing work on a project where I'm trying to make things as Conan 2.0 as possible, using CMakeToolchain and the new VirtualBuildEnv.

We have path variables that I figured out have to go into [buildenv], and that the syntax for prepending to the path is =+(path), like this compatible profile example.

include(llvm-toolset-7)
[env]
PATH=[/opt/cmake-3.19/bin]
[buildenv]
PATH=+(path)/opt/cmake-3.19/bin

I figured this out from the code.

Now that PATH=+(path)/opt/cmake-3.19/bin syntax looks familiar to me, and I thought I saw it somewhere.

For the life of me, I can't find doc on this. Am I missing something?