With commit R11:56538adacf53391307f687155be3fc787a95f40b to ports, I noticed an issue with poudriere, I was not able to disble using ccache for single ports (depending on cmake) by defining `NO_CCACHE`, looks like this commit ignores that varaible.
I also noticed that the commit hardcodes "ccache" as a binary name.
My patch puts the stanza in the general conditional so it is enabled only when ccache is being actually used. I'm also making the value use the variable `CCACHE_BIN`, which could be configured by the user.
Finally I also define the `CMAKE_CPP_COMPILER_LAUNCHER` variable, which could be needed by some projects.